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Class: Time

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Instance Chain:
self, ::Comparable
Inherits: Object
Defined in: time.c

Overview

Time is an abstraction of dates and times. Time is stored internally as the number of seconds with subsecond since the Epoch, 1970-01-01 00:00:00 UTC.

The Time class treats GMT (Greenwich Mean Time) and UTC (Coordinated Universal Time) as equivalent. GMT is the older way of referring to these baseline times but persists in the names of calls on POSIX systems.

All times may have subsecond. Be aware of this fact when comparing times with each other – times that are apparently equal when displayed may be different when compared. (Since Ruby 2.7.0, #inspect shows subsecond but #to_s still doesn’t show subsecond.)

Since Ruby 1.9.2, Time implementation uses a signed 63 bit integer, Bignum or ::Rational. The integer is a number of nanoseconds since the Epoch which can represent 1823-11-12 to 2116-02-20. When Bignum or ::Rational is used (before 1823, after 2116, under nanosecond), Time works slower as when integer is used.

Examples

All of these examples were done using the EST timezone which is GMT-5.

Creating a new Time instance

You can create a new instance of Time with .new. This will use the current system time. .now is an alias for this. You can also pass parts of the time to .new such as year, month, minute, etc. When you want to construct a time this way you must pass at least a year. If you pass the year with nothing else time will default to January 1 of that year at 00:00:00 with the current system timezone. Here are some examples:

Time.new(2002)         #=> 2002-01-01 00:00:00 -0500
Time.new(2002, 10)     #=> 2002-10-01 00:00:00 -0500
Time.new(2002, 10, 31) #=> 2002-10-31 00:00:00 -0500

You can pass a UTC offset:

Time.new(2002, 10, 31, 2, 2, 2, "+02:00") #=> 2002-10-31 02:02:02 +0200

Or a timezone object:

tz = timezone("Europe/Athens") # Eastern European Time, UTC+2
Time.new(2002, 10, 31, 2, 2, 2, tz) #=> 2002-10-31 02:02:02 +0200

You can also use .local and .utc to infer local and UTC timezones instead of using the current system setting.

You can also create a new time using .at which takes the number of seconds (with subsecond) since the Unix Epoch.

Time.at(628232400) #=> 1989-11-28 00:00:00 -0500

Working with an instance of Time

Once you have an instance of Time there is a multitude of things you can do with it. Below are some examples. For all of the following examples, we will work on the assumption that you have done the following:

t = Time.new(1993, 02, 24, 12, 0, 0, "+09:00")

Was that a monday?

t.monday? #=> false

What year was that again?

t.year #=> 1993

Was it daylight savings at the time?

t.dst? #=> false

What’s the day a year later?

t + (60*60*24*365) #=> 1994-02-24 12:00:00 +0900

How many seconds was that since the Unix Epoch?

t.to_i #=> 730522800

You can also do standard functions like compare two times.

t1 = Time.new(2010)
t2 = Time.new(2011)

t1 == t2 #=> false
t1 == t1 #=> true
t1 <  t2 #=> true
t1 >  t2 #=> false

Time.new(2010,10,31).between?(t1, t2) #=> true

Timezone argument

A timezone argument must have local_to_utc and utc_to_local methods, and may have name, abbr, and #dst? methods.

The local_to_utc method should convert a Time-like object from the timezone to UTC, and utc_to_local is the opposite. The result also should be a Time or Time-like object (not necessary to be the same class). The #zone of the result is just ignored. Time-like argument to these methods is similar to a Time object in UTC without subsecond; it has attribute readers for the parts, e.g. #year, #month, and so on, and epoch time readers, #to_i. The subsecond attributes are fixed as 0, and #utc_offset, #zone, #isdst, and their aliases are same as a Time object in UTC. Also #to_time, #+, and #- methods are defined.

The name method is used for marshaling. If this method is not defined on a timezone object, Time objects using that timezone object can not be dumped by ::Marshal.

The abbr method is used by ‘%Z’ in #strftime.

The #dst? method is called with a Time value and should return whether the Time value is in daylight savings time in the zone.

Auto conversion to Timezone

At loading marshaled data, a timezone name will be converted to a timezone object by find_timezone class method, if the method is defined.

Similarly, that class method will be called when a timezone argument does not have the necessary methods mentioned above.

Class Method Summary

Instance Attribute Summary

Instance Method Summary

::Comparable - Included

#<

Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than 0.

#<=

Compares two objects based on the receiver’s #<=> method, returning true if it returns a value less than or equal to 0.

#==

Compares two objects based on the receiver’s #<=> method, returning true if it returns 0.

#>

Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than 0.

#>=

Compares two objects based on the receiver’s #<=> method, returning true if it returns a value greater than or equal to 0.

#between?

Returns false if obj #<=> min is less than zero or if obj #<=> max is greater than zero, true otherwise.

#clamp

In (min, max) form, returns min if obj #<=> min is less than zero, max if obj #<=> max is greater than zero, and obj otherwise.

Constructor Details

.newTime .new(year, month = nil, day = nil, hour = nil, min = nil, sec = nil, tz = nil) ⇒ Time

Returns a Time object.

It is initialized to the current system time if no argument is given.

Note: The new object will use the resolution available on your system clock, and may include subsecond.

If one or more arguments are specified, the time is initialized to the specified time.

#sec may have subsecond if it is a rational.

tz specifies the timezone. It can be an offset from UTC, given either as a string such as “+09:00” or a single letter “A”..“Z” excluding “J” (so-called military time zone), or as a number of seconds such as 32400. Or it can be a timezone object, see Timezone argument for details.

a = Time.new      #=> 2020-07-21 01:27:44.917547285 +0900
b = Time.new      #=> 2020-07-21 01:27:44.917617713 +0900
a == b            #=> false
"%.6f" % a.to_f   #=> "1595262464.917547"
"%.6f" % b.to_f   #=> "1595262464.917618"

Time.new(2008,6,21, 13,30,0, "+09:00") #=> 2008-06-21 13:30:00 +0900

# A trip for RubyConf 2007
t1 = Time.new(2007,11,1,15,25,0, "+09:00") # JST (Narita)
t2 = Time.new(2007,11,1,12, 5,0, "-05:00") # CDT (Minneapolis)
t3 = Time.new(2007,11,1,13,25,0, "-05:00") # CDT (Minneapolis)
t4 = Time.new(2007,11,1,16,53,0, "-04:00") # EDT (Charlotte)
t5 = Time.new(2007,11,5, 9,24,0, "-05:00") # EST (Charlotte)
t6 = Time.new(2007,11,5,11,21,0, "-05:00") # EST (Detroit)
t7 = Time.new(2007,11,5,13,45,0, "-05:00") # EST (Detroit)
t8 = Time.new(2007,11,6,17,10,0, "+09:00") # JST (Narita)
(t2-t1)/3600.0                             #=> 10.666666666666666
(t4-t3)/3600.0                             #=> 2.466666666666667
(t6-t5)/3600.0                             #=> 1.95
(t8-t7)/3600.0                             #=> 13.416666666666666
[ GitHub ]

  
# File 'time.c', line 2443

static VALUE
time_init(int argc, VALUE *argv, VALUE time)
{
    if (argc == 0)
        return time_init_0(time);
    else
        return time_init_1(argc, argv, time);
}

Class Method Details

.at(time) ⇒ Time .at(seconds_with_frac) ⇒ Time .at(seconds, microseconds_with_frac) ⇒ Time .at(seconds, milliseconds, :millisecond) ⇒ Time .at(seconds, microseconds, :usec) ⇒ Time .at(seconds, microseconds, :microsecond) ⇒ Time .at(seconds, nanoseconds, :nsec) ⇒ Time .at(seconds, nanoseconds, :nanosecond) ⇒ Time .at(time, in: tz) ⇒ Time .at(seconds_with_frac, in: tz) ⇒ Time .at(seconds, microseconds_with_frac, in: tz) ⇒ Time .at(seconds, milliseconds, :millisecond, in: tz) ⇒ Time .at(seconds, microseconds, :usec, in: tz) ⇒ Time .at(seconds, microseconds, :microsecond, in: tz) ⇒ Time .at(seconds, nanoseconds, :nsec, in: tz) ⇒ Time .at(seconds, nanoseconds, :nanosecond, in: tz) ⇒ Time

Creates a new Time object with the value given by time, the given number of seconds_with_frac, or seconds and microseconds_with_frac since the Epoch. seconds_with_frac and microseconds_with_frac can be an ::Integer, ::Float, ::Rational, or other ::Numeric.

If in argument is given, the result is in that timezone or UTC offset, or if a numeric argument is given, the result is in local time. The in argument accepts the same types of arguments as tz argument of .new: string, number of seconds, or a timezone object.

Time.at(0)                                #=> 1969-12-31 18:00:00 -0600
Time.at(Time.at(0))                       #=> 1969-12-31 18:00:00 -0600
Time.at(946702800)                        #=> 1999-12-31 23:00:00 -0600
Time.at(-284061600)                       #=> 1960-12-31 00:00:00 -0600
Time.at(946684800.2).usec                 #=> 200000
Time.at(946684800, 123456.789).nsec       #=> 123456789
Time.at(946684800, 123456789, :nsec).nsec #=> 123456789

Time.at(1582721899, in: "+09:00")         #=> 2020-02-26 21:58:19 +0900
Time.at(1582721899, in: "UTC")            #=> 2020-02-26 12:58:19 UTC
Time.at(1582721899, in: "C")              #=> 2020-02-26 13:58:19 +0300
Time.at(1582721899, in: 32400)            #=> 2020-02-26 21:58:19 +0900

require 'tzinfo'
Time.at(1582721899, in: TZInfo::Timezone.get('Europe/Kiev'))
                                          #=> 2020-02-26 14:58:19 +0200
[ GitHub ]

  
# File 'time.c', line 2831

static VALUE
time_s_at(int argc, VALUE *argv, VALUE klass)
{
    VALUE time, t, unit = Qundef, zone = Qundef, opts;
    VALUE vals[TMOPT_MAX_];
    wideval_t timew;

    argc = rb_scan_args(argc, argv, "12:", &time, &t, &unit, &opts);
    if (get_tmopt(opts, vals)) {
        zone = vals[0];
    }
    if (argc >= 2) {
        int scale = argc == 3 ? get_scale(unit) : 1000000;
        time = num_exact(time);
        t = num_exact(t);
        timew = wadd(rb_time_magnify(v2w(time)), wmulquoll(v2w(t), TIME_SCALE, scale));
        t = time_new_timew(klass, timew);
    }
    else if (IsTimeval(time)) {
	struct time_object *tobj, *tobj2;
        GetTimeval(time, tobj);
        t = time_new_timew(klass, tobj->timew);
	GetTimeval(t, tobj2);
        TZMODE_COPY(tobj2, tobj);
    }
    else {
        timew = rb_time_magnify(v2w(num_exact(time)));
        t = time_new_timew(klass, timew);
    }
    if (zone != Qundef) {
        time_zonelocal(t, zone);
    }

    return t;
}

.utc(year) ⇒ Time .utc(year, month) ⇒ Time .utc(year, month, day) ⇒ Time .utc(year, month, day, hour) ⇒ Time .utc(year, month, day, hour, min) ⇒ Time .utc(year, month, day, hour, min, sec_with_frac) ⇒ Time .utc(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .utc(sec, min, hour, day, month, year, dummy, dummy, dummy, dummy) ⇒ Time .gm(year) ⇒ Time .gm(year, month) ⇒ Time .gm(year, month, day) ⇒ Time .gm(year, month, day, hour) ⇒ Time .gm(year, month, day, hour, min) ⇒ Time .gm(year, month, day, hour, min, sec_with_frac) ⇒ Time .gm(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .gm(sec, min, hour, day, month, year, dummy, dummy, dummy, dummy) ⇒ Time
Also known as: .utc

Creates a Time object based on given values, interpreted as UTC (GMT). The year must be specified. Other values default to the minimum value for that field (and may be nil or omitted). Months may be specified by numbers from 1 to 12, or by the three-letter English month names. Hours are specified on a 24-hour clock (0..23). Raises an ::ArgumentError if any values are out of range. Will also accept ten arguments in the order output by #to_a.

sec_with_frac and usec_with_frac can have a fractional part.

Time.utc(2000,"jan",1,20,15,1)  #=> 2000-01-01 20:15:01 UTC
Time.gm(2000,"jan",1,20,15,1)   #=> 2000-01-01 20:15:01 UTC
[ GitHub ]

  
# File 'time.c', line 3493

static VALUE
time_s_mkutc(int argc, VALUE *argv, VALUE klass)
{
    struct vtm vtm;

    time_arg(argc, argv, &vtm);
    return time_gmtime(time_new_timew(klass, timegmw(&vtm)));
}

.local(year) ⇒ Time .local(year, month) ⇒ Time .local(year, month, day) ⇒ Time .local(year, month, day, hour) ⇒ Time .local(year, month, day, hour, min) ⇒ Time .local(year, month, day, hour, min, sec_with_frac) ⇒ Time .local(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .local(sec, min, hour, day, month, year, dummy, dummy, isdst, dummy) ⇒ Time .mktime(year) ⇒ Time .mktime(year, month) ⇒ Time .mktime(year, month, day) ⇒ Time .mktime(year, month, day, hour) ⇒ Time .mktime(year, month, day, hour, min) ⇒ Time .mktime(year, month, day, hour, min, sec_with_frac) ⇒ Time .mktime(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .mktime(sec, min, hour, day, month, year, dummy, dummy, isdst, dummy) ⇒ Time
Also known as: .mktime

Same as .utc, but interprets the values in the local time zone.

Time.local(2000,"jan",1,20,15,1)   #=> 2000-01-01 20:15:01 -0600
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# File 'time.c', line 3527

static VALUE
time_s_mktime(int argc, VALUE *argv, VALUE klass)
{
    struct vtm vtm;

    time_arg(argc, argv, &vtm);
    return time_localtime(time_new_timew(klass, timelocalw(&vtm)));
}

.local(year) ⇒ Time .local(year, month) ⇒ Time .local(year, month, day) ⇒ Time .local(year, month, day, hour) ⇒ Time .local(year, month, day, hour, min) ⇒ Time .local(year, month, day, hour, min, sec_with_frac) ⇒ Time .local(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .local(sec, min, hour, day, month, year, dummy, dummy, isdst, dummy) ⇒ Time .mktime(year) ⇒ Time .mktime(year, month) ⇒ Time .mktime(year, month, day) ⇒ Time .mktime(year, month, day, hour) ⇒ Time .mktime(year, month, day, hour, min) ⇒ Time .mktime(year, month, day, hour, min, sec_with_frac) ⇒ Time .mktime(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .mktime(sec, min, hour, day, month, year, dummy, dummy, isdst, dummy) ⇒ Time

Alias for .local.

.nowTime

Creates a new Time object for the current time. This is same as .new without arguments.

Time.now            #=> 2009-06-24 12:39:54 +0900
[ GitHub ]

  
# File 'time.c', line 2752

static VALUE
time_s_now(int argc, VALUE *argv, VALUE klass)
{
    VALUE vals[TMOPT_MAX_], opts, t, zone = Qundef;
    rb_scan_args(argc, argv, ":", &opts);
    if (get_tmopt(opts, vals)) zone = vals[TMOPT_IN];
    t = rb_class_new_instance(0, NULL, klass);
    if (zone != Qundef) {
        time_zonelocal(t, zone);
    }
    return t;
}

.utc(year) ⇒ Time .utc(year, month) ⇒ Time .utc(year, month, day) ⇒ Time .utc(year, month, day, hour) ⇒ Time .utc(year, month, day, hour, min) ⇒ Time .utc(year, month, day, hour, min, sec_with_frac) ⇒ Time .utc(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .utc(sec, min, hour, day, month, year, dummy, dummy, dummy, dummy) ⇒ Time .gm(year) ⇒ Time .gm(year, month) ⇒ Time .gm(year, month, day) ⇒ Time .gm(year, month, day, hour) ⇒ Time .gm(year, month, day, hour, min) ⇒ Time .gm(year, month, day, hour, min, sec_with_frac) ⇒ Time .gm(year, month, day, hour, min, sec, usec_with_frac) ⇒ Time .gm(sec, min, hour, day, month, year, dummy, dummy, dummy, dummy) ⇒ Time

Alias for .gm.

Instance Attribute Details

#isdstBoolean (readonly) #dst?Boolean
Also known as: #isdst

Returns true if time occurs during Daylight Saving Time in its time zone.

# CST6CDT:
  Time.local(2000, 1, 1).zone    #=> "CST"
  Time.local(2000, 1, 1).isdst   #=> false
  Time.local(2000, 1, 1).dst?    #=> false
  Time.local(2000, 7, 1).zone    #=> "CDT"
  Time.local(2000, 7, 1).isdst   #=> true
  Time.local(2000, 7, 1).dst?    #=> true

# Asia/Tokyo:
  Time.local(2000, 1, 1).zone    #=> "JST"
  Time.local(2000, 1, 1).isdst   #=> false
  Time.local(2000, 1, 1).dst?    #=> false
  Time.local(2000, 7, 1).zone    #=> "JST"
  Time.local(2000, 7, 1).isdst   #=> false
  Time.local(2000, 7, 1).dst?    #=> false
[ GitHub ]

  
# File 'time.c', line 4738

static VALUE
time_isdst(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    if (tobj->vtm.isdst == VTM_ISDST_INITVAL) {
        rb_raise(rb_eRuntimeError, "isdst is not set yet");
    }
    return tobj->vtm.isdst ? Qtrue : Qfalse;
}

#friday?Boolean (readonly)

Returns true if time represents Friday.

t = Time.local(1987, 12, 18)     #=> 1987-12-18 00:00:00 -0600
t.friday?                        #=> true
[ GitHub ]

  
# File 'time.c', line 4671

static VALUE
time_friday(VALUE time)
{
    wday_p(5);
}

#utc?Boolean (readonly) #gmt?Boolean
Also known as: #utc?

Returns true if time represents a time in UTC (GMT).

t = Time.now                        #=> 2007-11-19 08:15:23 -0600
t.utc?                              #=> false
t = Time.gm(2000,"jan",1,20,15,1)   #=> 2000-01-01 20:15:01 UTC
t.utc?                              #=> true

t = Time.now                        #=> 2007-11-19 08:16:03 -0600
t.gmt?                              #=> false
t = Time.gm(2000,1,1,20,15,1)       #=> 2000-01-01 20:15:01 UTC
t.gmt?                              #=> true
[ GitHub ]

  
# File 'time.c', line 3795

static VALUE
time_utc_p(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    if (TZMODE_UTC_P(tobj)) return Qtrue;
    return Qfalse;
}

#isdstBoolean (readonly) #dst?Boolean

Alias for #dst?.

#monday?Boolean (readonly)

Returns true if time represents Monday.

t = Time.local(2003, 8, 4)       #=> 2003-08-04 00:00:00 -0500
t.monday?                        #=> true
[ GitHub ]

  
# File 'time.c', line 4607

static VALUE
time_monday(VALUE time)
{
    wday_p(1);
}

#saturday?Boolean (readonly)

Returns true if time represents Saturday.

t = Time.local(2006, 6, 10)      #=> 2006-06-10 00:00:00 -0500
t.saturday?                      #=> true
[ GitHub ]

  
# File 'time.c', line 4687

static VALUE
time_saturday(VALUE time)
{
    wday_p(6);
}

#sunday?Boolean (readonly)

Returns true if time represents Sunday.

t = Time.local(1990, 4, 1)       #=> 1990-04-01 00:00:00 -0600
t.sunday?                        #=> true
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# File 'time.c', line 4591

static VALUE
time_sunday(VALUE time)
{
    wday_p(0);
}

#thursday?Boolean (readonly)

Returns true if time represents Thursday.

t = Time.local(1995, 12, 21)     #=> 1995-12-21 00:00:00 -0600
t.thursday?                      #=> true
[ GitHub ]

  
# File 'time.c', line 4655

static VALUE
time_thursday(VALUE time)
{
    wday_p(4);
}

#tuesday?Boolean (readonly)

Returns true if time represents Tuesday.

t = Time.local(1991, 2, 19)      #=> 1991-02-19 00:00:00 -0600
t.tuesday?                       #=> true
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# File 'time.c', line 4623

static VALUE
time_tuesday(VALUE time)
{
    wday_p(2);
}

#utc?Boolean (readonly) #gmt?Boolean

Alias for #gmt?.

#wednesday?Boolean (readonly)

Returns true if time represents Wednesday.

t = Time.local(1993, 2, 24)      #=> 1993-02-24 00:00:00 -0600
t.wednesday?                     #=> true
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# File 'time.c', line 4639

static VALUE
time_wednesday(VALUE time)
{
    wday_p(3);
}

Instance Method Details

#+(numeric) ⇒ Time

Adds some number of seconds (possibly including subsecond) to time and returns that value as a new Time object.

t = Time.now         #=> 2020-07-20 22:14:43.170490982 +0900
t + (60 * 60 * 24)   #=> 2020-07-21 22:14:43.170490982 +0900
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# File 'time.c', line 4221

static VALUE
time_plus(VALUE time1, VALUE time2)
{
    struct time_object *tobj;
    GetTimeval(time1, tobj);

    if (IsTimeval(time2)) {
	rb_raise(rb_eTypeError, "time + time?");
    }
    return time_add(tobj, time1, time2, 1);
}

#-(other_time) ⇒ Float #-(numeric) ⇒ Time

Returns a difference in seconds as a ::Float between time and other_time, or subtracts the given number of seconds in numeric from time.

t = Time.now       #=> 2020-07-20 22:15:49.302766336 +0900
t2 = t + 2592000   #=> 2020-08-19 22:15:49.302766336 +0900
t2 - t             #=> 2592000.0
t2 - 2592000       #=> 2020-07-20 22:15:49.302766336 +0900
[ GitHub ]

  
# File 'time.c', line 4248

static VALUE
time_minus(VALUE time1, VALUE time2)
{
    struct time_object *tobj;

    GetTimeval(time1, tobj);
    if (IsTimeval(time2)) {
	struct time_object *tobj2;

	GetTimeval(time2, tobj2);
        return rb_Float(rb_time_unmagnify_to_float(wsub(tobj->timew, tobj2->timew)));
    }
    return time_add(tobj, time1, time2, -1);
}

#<=>(other_time) ⇒ 1, ...

Compares time with other_time.

-1, 0, +1 or nil depending on whether time is less than, equal to, or greater than other_time.

nil is returned if the two values are incomparable.

t = Time.now       #=> 2007-11-19 08:12:12 -0600
t2 = t + 2592000   #=> 2007-12-19 08:12:12 -0600
t <=> t2           #=> -1
t2 <=> t           #=> 1

t = Time.now       #=> 2007-11-19 08:13:38 -0600
t2 = t + 0.1       #=> 2007-11-19 08:13:38 -0600
t.nsec             #=> 98222999
t2.nsec            #=> 198222999
t <=> t2           #=> -1
t2 <=> t           #=> 1
t <=> t            #=> 0
[ GitHub ]

  
# File 'time.c', line 3737

static VALUE
time_cmp(VALUE time1, VALUE time2)
{
    struct time_object *tobj1, *tobj2;
    int n;

    GetTimeval(time1, tobj1);
    if (IsTimeval(time2)) {
	GetTimeval(time2, tobj2);
	n = wcmp(tobj1->timew, tobj2->timew);
    }
    else {
	return rb_invcmp(time1, time2);
    }
    if (n == 0) return INT2FIX(0);
    if (n > 0) return INT2FIX(1);
    return INT2FIX(-1);
}

#_dump(*args) (private)

This method is for internal use only.
[ GitHub ]

  
# File 'time.c', line 5250

static VALUE
time_dump(int argc, VALUE *argv, VALUE time)
{
    VALUE str;

    rb_check_arity(argc, 0, 1);
    str = time_mdump(time);

    return str;
}

#asctimeString #ctimeString

Alias for #ctime.

#ceil([ndigits]) ⇒ Time

Ceils subsecond to a given precision in decimal digits (0 digits by default). It returns a new Time object. ndigits should be zero or a positive integer.

t = Time.utc(2010,3,30, 5,43,25.0123456789r)
t                      #=> 2010-03-30 05:43:25 123456789/10000000000 UTC
t.ceil                 #=> 2010-03-30 05:43:26 UTC
t.ceil(0)              #=> 2010-03-30 05:43:26 UTC
t.ceil(1)              #=> 2010-03-30 05:43:25.1 UTC
t.ceil(2)              #=> 2010-03-30 05:43:25.02 UTC
t.ceil(3)              #=> 2010-03-30 05:43:25.013 UTC
t.ceil(4)              #=> 2010-03-30 05:43:25.0124 UTC

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.4).ceil         #=> 2000-01-01 00:00:00 UTC
(t + 0.9).ceil         #=> 2000-01-01 00:00:00 UTC
(t + 1.4).ceil         #=> 2000-01-01 00:00:01 UTC
(t + 1.9).ceil         #=> 2000-01-01 00:00:01 UTC

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.123456789).ceil(4)  #=> 1999-12-31 23:59:59.1235 UTC
[ GitHub ]

  
# File 'time.c', line 4400

static VALUE
time_ceil(int argc, VALUE *argv, VALUE time)
{
    VALUE ndigits, v, den;
    struct time_object *tobj;

    if (!rb_check_arity(argc, 0, 1) || NIL_P(ndigits = argv[0]))
        den = INT2FIX(1);
    else
        den = ndigits_denominator(ndigits);

    GetTimeval(time, tobj);
    v = w2v(rb_time_unmagnify(tobj->timew));

    v = modv(v, den);
    if (!rb_equal(v, INT2FIX(0))) {
        v = subv(den, v);
    }
    return time_add(tobj, time, v, 1);
}

#asctimeString #ctimeString
Also known as: #asctime

Returns a canonical string representation of time.

Time.now.asctime   #=> "Wed Apr  9 08:56:03 2003"
Time.now.ctime     #=> "Wed Apr  9 08:56:03 2003"
[ GitHub ]

  
# File 'time.c', line 4107

static VALUE
time_asctime(VALUE time)
{
    return strftimev("%a %b %e %T %Y", time, rb_usascii_encoding());
}

#dayInteger #mdayInteger
Also known as: #mday

Returns the day of the month (1..31) for time.

t = Time.now   #=> 2007-11-19 08:27:03 -0600
t.day          #=> 19
t.mday         #=> 19
[ GitHub ]

  
# File 'time.c', line 4497

static VALUE
time_mday(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    return INT2FIX(tobj->vtm.mday);
}

#eql?(other_time)

Returns true if time and other_time are both Time objects with the same seconds (including subsecond) from the Epoch.

[ GitHub ]

  
# File 'time.c', line 3764

static VALUE
time_eql(VALUE time1, VALUE time2)
{
    struct time_object *tobj1, *tobj2;

    GetTimeval(time1, tobj1);
    if (IsTimeval(time2)) {
	GetTimeval(time2, tobj2);
        return rb_equal(w2v(tobj1->timew), w2v(tobj2->timew));
    }
    return Qfalse;
}

#floor([ndigits]) ⇒ Time

Floors subsecond to a given precision in decimal digits (0 digits by default). It returns a new Time object. ndigits should be zero or a positive integer.

t = Time.utc(2010,3,30, 5,43,25.123456789r)
t                       #=> 2010-03-30 05:43:25.123456789 UTC
t.floor                 #=> 2010-03-30 05:43:25 UTC
t.floor(0)              #=> 2010-03-30 05:43:25 UTC
t.floor(1)              #=> 2010-03-30 05:43:25.1 UTC
t.floor(2)              #=> 2010-03-30 05:43:25.12 UTC
t.floor(3)              #=> 2010-03-30 05:43:25.123 UTC
t.floor(4)              #=> 2010-03-30 05:43:25.1234 UTC

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.4).floor    #=> 1999-12-31 23:59:59 UTC
(t + 0.9).floor    #=> 1999-12-31 23:59:59 UTC
(t + 1.4).floor    #=> 2000-01-01 00:00:00 UTC
(t + 1.9).floor    #=> 2000-01-01 00:00:00 UTC

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.123456789).floor(4)  #=> 1999-12-31 23:59:59.1234 UTC
[ GitHub ]

  
# File 'time.c', line 4355

static VALUE
time_floor(int argc, VALUE *argv, VALUE time)
{
    VALUE ndigits, v, den;
    struct time_object *tobj;

    if (!rb_check_arity(argc, 0, 1) || NIL_P(ndigits = argv[0]))
        den = INT2FIX(1);
    else
        den = ndigits_denominator(ndigits);

    GetTimeval(time, tobj);
    v = w2v(rb_time_unmagnify(tobj->timew));

    v = modv(v, den);
    return time_add(tobj, time, v, -1);
}

#getgmTime #getutcTime
Also known as: #getutc

Returns a new Time object representing time in UTC.

t = Time.local(2000,1,1,20,15,1)   #=> 2000-01-01 20:15:01 -0600
t.gmt?                             #=> false
y = t.getgm                        #=> 2000-01-02 02:15:01 UTC
y.gmt?                             #=> true
t == y                             #=> true
[ GitHub ]

  
# File 'time.c', line 4079

static VALUE
time_getgmtime(VALUE time)
{
    return time_gmtime(time_dup(time));
}

#getlocalTime #getlocal(utc_offset) ⇒ Time #getlocal(timezone) ⇒ Time

Returns a new Time object representing time in local time (using the local time zone in effect for this process).

If #utc_offset is given, it is used instead of the local time. #utc_offset can be given as a human-readable string (eg. "+09:00") or as a number of seconds (eg. 32400).

t = Time.utc(2000,1,1,20,15,1)  #=> 2000-01-01 20:15:01 UTC
t.utc?                          #=> true

l = t.getlocal                  #=> 2000-01-01 14:15:01 -0600
l.utc?                          #=> false
t == l                          #=> true

j = t.getlocal("+09:00")        #=> 2000-01-02 05:15:01 +0900
j.utc?                          #=> false
t == j                          #=> true

k = t.getlocal(9*60*60)         #=> 2000-01-02 05:15:01 +0900
k.utc?                          #=> false
t == k                          #=> true
[ GitHub ]

  
# File 'time.c', line 4034

static VALUE
time_getlocaltime(int argc, VALUE *argv, VALUE time)
{
    VALUE off;

    if (rb_check_arity(argc, 0, 1) && !NIL_P(off = argv[0])) {
        VALUE zone = off;
        if (maybe_tzobj_p(zone)) {
            VALUE t = time_dup(time);
            if (zone_localtime(off, t)) return t;
        }

        if (NIL_P(off = utc_offset_arg(off))) {
            if (NIL_P(zone = find_timezone(time, zone))) invalid_utc_offset();
            time = time_dup(time);
            if (!zone_localtime(zone, time)) invalid_utc_offset();
            return time;
        }
        else if (off == UTC_ZONE) {
            return time_gmtime(time_dup(time));
        }
        validate_utc_offset(off);

        time = time_dup(time);
        time_set_utc_offset(time, off);
        return time_fixoff(time);
    }

    return time_localtime(time_dup(time));
}

#getgmTime #getutcTime

Alias for #getgm.

#gmt_offsetInteger #gmtoffInteger #utc_offsetInteger

Alias for #gmtoff.

#gmtimeTime #utcTime

Alias for #utc.

#gmt_offsetInteger #gmtoffInteger #utc_offsetInteger
Also known as: #gmt_offset, #utc_offset

Returns the offset in seconds between the timezone of time and UTC.

t = Time.gm(2000,1,1,20,15,1)   #=> 2000-01-01 20:15:01 UTC
t.gmt_offset                    #=> 0
l = t.getlocal                  #=> 2000-01-01 14:15:01 -0600
l.gmt_offset                    #=> -21600
[ GitHub ]

  
# File 'time.c', line 4800

VALUE
rb_time_utc_offset(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);

    if (TZMODE_UTC_P(tobj)) {
	return INT2FIX(0);
    }
    else {
	MAKE_TM(time, tobj);
	return tobj->vtm.utc_offset;
    }
}

#hashInteger

Returns a hash code for this Time object.

See also Object#hash.

[ GitHub ]

  
# File 'time.c', line 3814

static VALUE
time_hash(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    return rb_hash(w2v(tobj->timew));
}

#hourInteger

Returns the hour of the day (0..23) for time.

t = Time.now   #=> 2007-11-19 08:26:20 -0600
t.hour         #=> 8
[ GitHub ]

  
# File 'time.c', line 4475

static VALUE
time_hour(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    return INT2FIX(tobj->vtm.hour);
}

#initialize_copy(time)

This method is for internal use only.
[ GitHub ]

  
# File 'time.c', line 3824

static VALUE
time_init_copy(VALUE copy, VALUE time)
{
    struct time_object *tobj, *tcopy;

    if (!OBJ_INIT_COPY(copy, time)) return copy;
    GetTimeval(time, tobj);
    GetNewTimeval(copy, tcopy);
    MEMCPY(tcopy, tobj, struct time_object, 1);

    return copy;
}

#inspectString

Returns a detailed string representing time. Unlike to_s, preserves subsecond in the representation for easier debugging.

t = Time.now
t.inspect                             #=> "2012-11-10 18:16:12.261257655 +0100"
t.strftime "%Y-%m-%d %H:%M:%S.%N %z"  #=> "2012-11-10 18:16:12.261257655 +0100"

t.utc.inspect                          #=> "2012-11-10 17:16:12.261257655 UTC"
t.strftime "%Y-%m-%d %H:%M:%S.%N UTC"  #=> "2012-11-10 17:16:12.261257655 UTC"
[ GitHub ]

  
# File 'time.c', line 4155

static VALUE
time_inspect(VALUE time)
{
    struct time_object *tobj;
    VALUE str, subsec;

    GetTimeval(time, tobj);
    str = strftimev("%Y-%m-%d %H:%M:%S", time, rb_usascii_encoding());
    subsec = w2v(wmod(tobj->timew, WINT2FIXWV(TIME_SCALE)));
    if (FIXNUM_P(subsec) && FIX2LONG(subsec) == 0) {
    }
    else if (FIXNUM_P(subsec) && FIX2LONG(subsec) < TIME_SCALE) {
        long len;
        rb_str_catf(str, ".%09ld", FIX2LONG(subsec));
        for (len=RSTRING_LEN(str); RSTRING_PTR(str)[len-1] == '0' && len > 0; len--)
            ;
        rb_str_resize(str, len);
    }
    else {
        rb_str_cat_cstr(str, " ");
        subsec = quov(subsec, INT2FIX(TIME_SCALE));
        rb_str_concat(str, rb_obj_as_string(subsec));
    }
    if (TZMODE_UTC_P(tobj)) {
        rb_str_cat_cstr(str, " UTC");
    }
    else {
        rb_str_concat(str, strftimev(" %z", time, rb_usascii_encoding()));
    }
    return str;
}

#localtimeTime #localtime(utc_offset) ⇒ Time

Converts time to local time (using the local time zone in effect at the creation time of time) modifying the receiver.

If #utc_offset is given, it is used instead of the local time.

t = Time.utc(2000, "jan", 1, 20, 15, 1) #=> 2000-01-01 20:15:01 UTC
t.utc?                                  #=> true

t.localtime                             #=> 2000-01-01 14:15:01 -0600
t.utc?                                  #=> false

t.localtime("+09:00")                   #=> 2000-01-02 05:15:01 +0900
t.utc?                                  #=> false

If #utc_offset is not given and time is local time, just returns the receiver.

[ GitHub ]

  
# File 'time.c', line 3918

static VALUE
time_localtime_m(int argc, VALUE *argv, VALUE time)
{
    VALUE off;

    if (rb_check_arity(argc, 0, 1) && !NIL_P(off = argv[0])) {
        return time_zonelocal(time, off);
    }

    return time_localtime(time);
}

#marshal_dump (private)

This method is for internal use only.
[ GitHub ]

  
# File 'time.c', line 5108

static VALUE
time_mdump(VALUE time)
{
    struct time_object *tobj;
    unsigned long p, s;
    char buf[base_dump_size + sizeof(long) + 1];
    int i;
    VALUE str;

    struct vtm vtm;
    long year;
    long usec, nsec;
    VALUE subsecx, nano, subnano, v, zone;

    VALUE year_extend = Qnil;
    const int max_year = 1900+0xffff;

    GetTimeval(time, tobj);

    gmtimew(tobj->timew, &vtm);

    if (FIXNUM_P(vtm.year)) {
        year = FIX2LONG(vtm.year);
        if (year > max_year) {
            year_extend = INT2FIX(year - max_year);
            year = max_year;
        }
        else if (year < 1900) {
            year_extend = LONG2NUM(1900 - year);
            year = 1900;
        }
    }
    else {
        if (rb_int_positive_p(vtm.year)) {
            year_extend = rb_int_minus(vtm.year, INT2FIX(max_year));
            year = max_year;
        }
        else {
            year_extend = rb_int_minus(INT2FIX(1900), vtm.year);
            year = 1900;
        }
    }

    subsecx = vtm.subsecx;

    nano = mulquov(subsecx, INT2FIX(1000000000), INT2FIX(TIME_SCALE));
    divmodv(nano, INT2FIX(1), &v, &subnano);
    nsec = FIX2LONG(v);
    usec = nsec / 1000;
    nsec = nsec % 1000;

    nano = addv(LONG2FIX(nsec), subnano);

    p = 0x1UL            << 31 | /*  1 */
	TZMODE_UTC_P(tobj) << 30 | /*  1 */
	(year-1900)      << 14 | /* 16 */
	(vtm.mon-1)      << 10 | /*  4 */
	vtm.mday         <<  5 | /*  5 */
	vtm.hour;                /*  5 */
    s = (unsigned long)vtm.min << 26 | /*  6 */
	vtm.sec          << 20 | /*  6 */
	usec;    /* 20 */

    for (i=0; i<4; i++) {
	buf[i] = (unsigned char)p;
	p = RSHIFT(p, 8);
    }
    for (i=4; i<8; i++) {
	buf[i] = (unsigned char)s;
	s = RSHIFT(s, 8);
    }

    if (!NIL_P(year_extend)) {
        /*
         * Append extended year distance from 1900..(1900+0xffff).  In
         * each cases, there is no sign as the value is positive.  The
         * format is length (marshaled long) + little endian packed
         * binary (like as Fixnum and Bignum).
         */
        size_t ysize = rb_absint_size(year_extend, NULL);
        char *p, *const buf_year_extend = buf + base_dump_size;
        if (ysize > LONG_MAX ||
            (i = ruby_marshal_write_long((long)ysize, buf_year_extend)) < 0) {
            rb_raise(rb_eArgError, "year too %s to marshal: %"PRIsVALUE" UTC",
                     (year == 1900 ? "small" : "big"), vtm.year);
        }
        i += base_dump_size;
        str = rb_str_new(NULL, i + ysize);
        p = RSTRING_PTR(str);
        memcpy(p, buf, i);
        p += i;
        rb_integer_pack(year_extend, p, ysize, 1, 0, INTEGER_PACK_LITTLE_ENDIAN);
    }
    else {
        str = rb_str_new(buf, base_dump_size);
    }
    rb_copy_generic_ivar(str, time);
    if (!rb_equal(nano, INT2FIX(0))) {
        if (RB_TYPE_P(nano, T_RATIONAL)) {
            rb_ivar_set(str, id_nano_num, RRATIONAL(nano)->num);
            rb_ivar_set(str, id_nano_den, RRATIONAL(nano)->den);
        }
        else {
            rb_ivar_set(str, id_nano_num, nano);
            rb_ivar_set(str, id_nano_den, INT2FIX(1));
        }
    }
    if (nsec) { /* submicro is only for Ruby 1.9.1 compatibility */
        /*
         * submicro is formatted in fixed-point packed BCD (without sign).
         * It represent digits under microsecond.
         * For nanosecond resolution, 3 digits (2 bytes) are used.
         * However it can be longer.
         * Extra digits are ignored for loading.
         */
        char buf[2];
        int len = (int)sizeof(buf);
        buf[1] = (char)((nsec % 10) << 4);
        nsec /= 10;
        buf[0] = (char)(nsec % 10);
        nsec /= 10;
        buf[0] |= (char)((nsec % 10) << 4);
        if (buf[1] == 0)
            len = 1;
        rb_ivar_set(str, id_submicro, rb_str_new(buf, len));
    }
    if (!TZMODE_UTC_P(tobj)) {
	VALUE off = rb_time_utc_offset(time), div, mod;
	divmodv(off, INT2FIX(1), &div, &mod);
	if (rb_equal(mod, INT2FIX(0)))
	    off = rb_Integer(div);
	rb_ivar_set(str, id_offset, off);
    }
    zone = tobj->vtm.zone;
    if (maybe_tzobj_p(zone)) {
        zone = rb_funcallv(zone, id_name, 0, 0);
    }
    rb_ivar_set(str, id_zone, zone);
    return str;
}

#marshal_load(str) (private)

This method is for internal use only.
[ GitHub ]

  
# File 'time.c', line 5284

static VALUE
time_mload(VALUE time, VALUE str)
{
    struct time_object *tobj;
    unsigned long p, s;
    time_t sec;
    long usec;
    unsigned char *buf;
    struct vtm vtm;
    int i, gmt;
    long nsec;
    VALUE submicro, nano_num, nano_den, offset, zone, year;
    wideval_t timew;

    time_modify(time);

#define get_attr(attr, iffound) \
    attr = rb_attr_delete(str, id_##attr); \
    if (!NIL_P(attr)) { \
	iffound; \
    }

    get_attr(nano_num, {});
    get_attr(nano_den, {});
    get_attr(submicro, {});
    get_attr(offset, (offset = rb_rescue(validate_utc_offset, offset, 0, Qnil)));
    get_attr(zone, (zone = rb_rescue(validate_zone_name, zone, 0, Qnil)));
    get_attr(year, {});

#undef get_attr

    rb_copy_generic_ivar(time, str);

    StringValue(str);
    buf = (unsigned char *)RSTRING_PTR(str);
    if (RSTRING_LEN(str) < base_dump_size) {
        goto invalid_format;
    }

    p = s = 0;
    for (i=0; i<4; i++) {
	p |= (unsigned long)buf[i]<<(8*i);
    }
    for (i=4; i<8; i++) {
	s |= (unsigned long)buf[i]<<(8*(i-4));
    }

    if ((p & (1UL<<31)) == 0) {
        gmt = 0;
	offset = Qnil;
	sec = p;
	usec = s;
        nsec = usec * 1000;
        timew = wadd(rb_time_magnify(TIMET2WV(sec)), wmulquoll(WINT2FIXWV(usec), TIME_SCALE, 1000000));
    }
    else {
	p &= ~(1UL<<31);
	gmt        = (int)((p >> 30) & 0x1);

        if (NIL_P(year)) {
            year = INT2FIX(((int)(p >> 14) & 0xffff) + 1900);
        }
        if (RSTRING_LEN(str) > base_dump_size) {
            long len = RSTRING_LEN(str) - base_dump_size;
            long ysize = 0;
            VALUE year_extend;
            const char *ybuf = (const char *)(buf += base_dump_size);
            ysize = ruby_marshal_read_long(&ybuf, len);
            len -= ybuf - (const char *)buf;
            if (ysize < 0 || ysize > len) goto invalid_format;
            year_extend = rb_integer_unpack(ybuf, ysize, 1, 0, INTEGER_PACK_LITTLE_ENDIAN);
            if (year == INT2FIX(1900)) {
                year = rb_int_minus(year, year_extend);
            }
            else {
                year = rb_int_plus(year, year_extend);
            }
        }
        vtm.year = year;
	vtm.mon  = ((int)(p >> 10) & 0xf) + 1;
	vtm.mday = (int)(p >>  5) & 0x1f;
	vtm.hour = (int) p        & 0x1f;
	vtm.min  = (int)(s >> 26) & 0x3f;
	vtm.sec  = (int)(s >> 20) & 0x3f;
        vtm.utc_offset = INT2FIX(0);
	vtm.yday = vtm.wday = 0;
	vtm.isdst = 0;
	vtm.zone = str_empty;

	usec = (long)(s & 0xfffff);
        nsec = usec * 1000;


        vtm.subsecx = mulquov(LONG2FIX(nsec), INT2FIX(TIME_SCALE), LONG2FIX(1000000000));
        if (nano_num != Qnil) {
            VALUE nano = quov(num_exact(nano_num), num_exact(nano_den));
            vtm.subsecx = addv(vtm.subsecx, mulquov(nano, INT2FIX(TIME_SCALE), LONG2FIX(1000000000)));
        }
        else if (submicro != Qnil) { /* for Ruby 1.9.1 compatibility */
            unsigned char *ptr;
            long len;
            int digit;
            ptr = (unsigned char*)StringValuePtr(submicro);
            len = RSTRING_LEN(submicro);
            nsec = 0;
            if (0 < len) {
                if (10 <= (digit = ptr[0] >> 4)) goto end_submicro;
                nsec += digit * 100;
                if (10 <= (digit = ptr[0] & 0xf)) goto end_submicro;
                nsec += digit * 10;
            }
            if (1 < len) {
                if (10 <= (digit = ptr[1] >> 4)) goto end_submicro;
                nsec += digit;
            }
            vtm.subsecx = addv(vtm.subsecx, mulquov(LONG2FIX(nsec), INT2FIX(TIME_SCALE), LONG2FIX(1000000000)));
end_submicro: ;
        }
        timew = timegmw(&vtm);
    }

    GetNewTimeval(time, tobj);
    tobj->tzmode = TIME_TZMODE_LOCALTIME;
    tobj->tm_got = 0;
    tobj->timew = timew;
    if (gmt) {
	TZMODE_SET_UTC(tobj);
    }
    else if (!NIL_P(offset)) {
	time_set_utc_offset(time, offset);
	time_fixoff(time);
    }
    if (!NIL_P(zone)) {
        zone = mload_zone(time, zone);
	tobj->vtm.zone = zone;
        zone_localtime(zone, time);
    }

    return time;

  invalid_format:
    rb_raise(rb_eTypeError, "marshaled time format differ");
    UNREACHABLE_RETURN(Qundef);
}

#dayInteger #mdayInteger

Alias for #day.

#minInteger

Returns the minute of the hour (0..59) for time.

t = Time.now   #=> 2007-11-19 08:25:51 -0600
t.min          #=> 25
[ GitHub ]

  
# File 'time.c', line 4455

static VALUE
time_min(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    return INT2FIX(tobj->vtm.min);
}

#monInteger #monthInteger
Also known as: #month

Returns the month of the year (1..12) for time.

t = Time.now   #=> 2007-11-19 08:27:30 -0600
t.mon          #=> 11
t.month        #=> 11
[ GitHub ]

  
# File 'time.c', line 4519

static VALUE
time_mon(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    return INT2FIX(tobj->vtm.mon);
}

#monInteger #monthInteger

Alias for #mon.

#nsecInteger #tv_nsecInteger
Also known as: #tv_nsec

Returns the number of nanoseconds for the subsecond part of time. The result is a non-negative integer less than 10**9.

t = Time.now        #=> 2020-07-20 22:07:10.963933942 +0900
t.nsec              #=> 963933942

If time has fraction of nanosecond (such as picoseconds), it is truncated.

t = Time.new(2000,1,1,0,0,0.666_777_888_999r)
t.nsec              #=> 666777888

#subsec can be used to obtain the subsecond part exactly.

[ GitHub ]

  
# File 'time.c', line 3673

static VALUE
time_nsec(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    return rb_to_int(w2v(wmulquoll(wmod(tobj->timew, WINT2WV(TIME_SCALE)), 1000000000, TIME_SCALE)));
}

#round([ndigits]) ⇒ Time

Rounds subsecond to a given precision in decimal digits (0 digits by default). It returns a new Time object. ndigits should be zero or a positive integer.

t = Time.utc(2010,3,30, 5,43,25.123456789r)
t                       #=> 2010-03-30 05:43:25.123456789 UTC
t.round                 #=> 2010-03-30 05:43:25 UTC
t.round(0)              #=> 2010-03-30 05:43:25 UTC
t.round(1)              #=> 2010-03-30 05:43:25.1 UTC
t.round(2)              #=> 2010-03-30 05:43:25.12 UTC
t.round(3)              #=> 2010-03-30 05:43:25.123 UTC
t.round(4)              #=> 2010-03-30 05:43:25.1235 UTC

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.4).round         #=> 1999-12-31 23:59:59 UTC
(t + 0.49).round        #=> 1999-12-31 23:59:59 UTC
(t + 0.5).round         #=> 2000-01-01 00:00:00 UTC
(t + 1.4).round         #=> 2000-01-01 00:00:00 UTC
(t + 1.49).round        #=> 2000-01-01 00:00:00 UTC
(t + 1.5).round         #=> 2000-01-01 00:00:01 UTC

t = Time.utc(1999,12,31, 23,59,59)     #=> 1999-12-31 23:59:59 UTC
(t + 0.123456789).round(4).iso8601(6)  #=> 1999-12-31 23:59:59.1235 UTC
[ GitHub ]

  
# File 'time.c', line 4307

static VALUE
time_round(int argc, VALUE *argv, VALUE time)
{
    VALUE ndigits, v, den;
    struct time_object *tobj;

    if (!rb_check_arity(argc, 0, 1) || NIL_P(ndigits = argv[0]))
        den = INT2FIX(1);
    else
        den = ndigits_denominator(ndigits);

    GetTimeval(time, tobj);
    v = w2v(rb_time_unmagnify(tobj->timew));

    v = modv(v, den);
    if (lt(v, quov(den, INT2FIX(2))))
        return time_add(tobj, time, v, -1);
    else
        return time_add(tobj, time, subv(den, v), 1);
}

#secInteger

Returns the second of the minute (0..60) for time.

Note: Seconds range from zero to 60 to allow the system to inject leap seconds. See en.wikipedia.org/wiki/Leap_second for further details.

t = Time.now   #=> 2007-11-19 08:25:02 -0600
t.sec          #=> 2
[ GitHub ]

  
# File 'time.c', line 4435

static VALUE
time_sec(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    return INT2FIX(tobj->vtm.sec);
}

#strftime(string) ⇒ String

Formats time according to the directives in the given format string.

The directives begin with a percent (%) character. Any text not listed as a directive will be passed through to the output string.

The directive consists of a percent (%) character, zero or more flags, optional minimum field width, optional modifier and a conversion specifier as follows:

%<flags><width><modifier><conversion>

Flags:

-  don't pad a numerical output
_  use spaces for padding
0  use zeros for padding
^  upcase the result string
#  change case
:  use colons for %z

The minimum field width specifies the minimum width.

The modifiers are “E” and “O”. They are ignored.

Format directives:

Date (Year, Month, Day):
  %Y - Year with century if provided, will pad result at least 4 digits.
          -0001, 0000, 1995, 2009, 14292, etc.
  %C - year / 100 (rounded down such as 20 in 2009)
  %y - year % 100 (00..99)

  %m - Month of the year, zero-padded (01..12)
          %_m  blank-padded ( 1..12)
          %-m  no-padded (1..12)
  %B - The full month name (``January'')
          %^B  uppercased (``JANUARY'')
  %b - The abbreviated month name (``Jan'')
          %^b  uppercased (``JAN'')
  %h - Equivalent to %b

  %d - Day of the month, zero-padded (01..31)
          %-d  no-padded (1..31)
  %e - Day of the month, blank-padded ( 1..31)

  %j - Day of the year (001..366)

Time (Hour, Minute, Second, Subsecond):
  %H - Hour of the day, 24-hour clock, zero-padded (00..23)
  %k - Hour of the day, 24-hour clock, blank-padded ( 0..23)
  %I - Hour of the day, 12-hour clock, zero-padded (01..12)
  %l - Hour of the day, 12-hour clock, blank-padded ( 1..12)
  %P - Meridian indicator, lowercase (``am'' or ``pm'')
  %p - Meridian indicator, uppercase (``AM'' or ``PM'')

  %M - Minute of the hour (00..59)

  %S - Second of the minute (00..60)

  %L - Millisecond of the second (000..999)
       The digits under millisecond are truncated to not produce 1000.
  %N - Fractional seconds digits, default is 9 digits (nanosecond)
          %3N  millisecond (3 digits)
          %6N  microsecond (6 digits)
          %9N  nanosecond (9 digits)
          %12N picosecond (12 digits)
          %15N femtosecond (15 digits)
          %18N attosecond (18 digits)
          %21N zeptosecond (21 digits)
          %24N yoctosecond (24 digits)
       The digits under the specified length are truncated to avoid
       carry up.

Time zone:
  %z - Time zone as hour and minute offset from UTC (e.g. +0900)
          %:z - hour and minute offset from UTC with a colon (e.g. +09:00)
          %::z - hour, minute and second offset from UTC (e.g. +09:00:00)
  %Z - Abbreviated time zone name or similar information.  (OS dependent)

Weekday:
  %A - The full weekday name (``Sunday'')
          %^A  uppercased (``SUNDAY'')
  %a - The abbreviated name (``Sun'')
          %^a  uppercased (``SUN'')
  %u - Day of the week (Monday is 1, 1..7)
  %w - Day of the week (Sunday is 0, 0..6)

ISO 8601 week-based year and week number:
The first week of YYYY starts with a Monday and includes YYYY-01-04.
The days in the year before the first week are in the last week of
the previous year.
  %G - The week-based year
  %g - The last 2 digits of the week-based year (00..99)
  %V - Week number of the week-based year (01..53)

Week number:
The first week of YYYY that starts with a Sunday or Monday (according to %U
or %W). The days in the year before the first week are in week 0.
  %U - Week number of the year. The week starts with Sunday. (00..53)
  %W - Week number of the year. The week starts with Monday. (00..53)

Seconds since the Epoch:
  %s - Number of seconds since 1970-01-01 00:00:00 UTC.

Literal string:
  %n - Newline character (\n)
  %t - Tab character (\t)
  %% - Literal ``%'' character

Combination:
  %c - date and time (%a %b %e %T %Y)
  %D - Date (%m/%d/%y)
  %F - The ISO 8601 date format (%Y-%m-%d)
  %v - VMS date (%e-%^b-%4Y)
  %x - Same as %D
  %X - Same as %T
  %r - 12-hour time (%I:%M:%S %p)
  %R - 24-hour time (%H:%M)
  %T - 24-hour time (%H:%M:%S)

This method is similar to strftime() function defined in ISO C and POSIX.

While all directives are locale independent since Ruby 1.9, %Z is platform dependent. So, the result may differ even if the same format string is used in other systems such as C.

%z is recommended over %Z. %Z doesn’t identify the timezone. For example, “CST” is used at America/Chicago (-06:00), America/Havana (-05:00), Asia/Harbin (+08:00), Australia/Darwin (+09:30) and Australia/Adelaide (+10:30). Also, %Z is highly dependent on the operating system. For example, it may generate a non ASCII string on Japanese Windows, i.e. the result can be different to “JST”. So the numeric time zone offset, %z, is recommended.

Examples:

t = Time.new(2007,11,19,8,37,48,"-06:00") #=> 2007-11-19 08:37:48 -0600
t.strftime("Printed on %m/%d/%Y")         #=> "Printed on 11/19/2007"
t.strftime("at %I:%M %p")                 #=> "at 08:37 AM"

Various ISO 8601 formats:

%Y%m%d           => 20071119                  Calendar date (basic)
%F               => 2007-11-19                Calendar date (extended)
%Y-%m            => 2007-11                   Calendar date, reduced accuracy, specific month
%Y               => 2007                      Calendar date, reduced accuracy, specific year
%C               => 20                        Calendar date, reduced accuracy, specific century
%Y%j             => 2007323                   Ordinal date (basic)
%Y-%j            => 2007-323                  Ordinal date (extended)
%GW%V%u          => 2007W471                  Week date (basic)
%G-W%V-%u        => 2007-W47-1                Week date (extended)
%GW%V            => 2007W47                   Week date, reduced accuracy, specific week (basic)
%G-W%V           => 2007-W47                  Week date, reduced accuracy, specific week (extended)
%H%M%S           => 083748                    Local time (basic)
%T               => 08:37:48                  Local time (extended)
%H%M             => 0837                      Local time, reduced accuracy, specific minute (basic)
%H:%M            => 08:37                     Local time, reduced accuracy, specific minute (extended)
%H               => 08                        Local time, reduced accuracy, specific hour
%H%M%S,%L        => 083748,000                Local time with decimal fraction, comma as decimal sign (basic)
%T,%L            => 08:37:48,000              Local time with decimal fraction, comma as decimal sign (extended)
%H%M%S.%L        => 083748.000                Local time with decimal fraction, full stop as decimal sign (basic)
%T.%L            => 08:37:48.000              Local time with decimal fraction, full stop as decimal sign (extended)
%H%M%S%z         => 083748-0600               Local time and the difference from UTC (basic)
%T%:z            => 08:37:48-06:00            Local time and the difference from UTC (extended)
%Y%m%dT%H%M%S%z  => 20071119T083748-0600      Date and time of day for calendar date (basic)
%FT%T%:z         => 2007-11-19T08:37:48-06:00 Date and time of day for calendar date (extended)
%Y%jT%H%M%S%z    => 2007323T083748-0600       Date and time of day for ordinal date (basic)
%Y-%jT%T%:z      => 2007-323T08:37:48-06:00   Date and time of day for ordinal date (extended)
%GW%V%uT%H%M%S%z => 2007W471T083748-0600      Date and time of day for week date (basic)
%G-W%V-%uT%T%:z  => 2007-W47-1T08:37:48-06:00 Date and time of day for week date (extended)
%Y%m%dT%H%M      => 20071119T0837             Calendar date and local time (basic)
%FT%R            => 2007-11-19T08:37          Calendar date and local time (extended)
%Y%jT%H%MZ       => 2007323T0837Z             Ordinal date and UTC of day (basic)
%Y-%jT%RZ        => 2007-323T08:37Z           Ordinal date and UTC of day (extended)
%GW%V%uT%H%M%z   => 2007W471T0837-0600        Week date and local time and difference from UTC (basic)
%G-W%V-%uT%R%:z  => 2007-W47-1T08:37-06:00    Week date and local time and difference from UTC (extended)
[ GitHub ]

  
# File 'time.c', line 5071

static VALUE
time_strftime(VALUE time, VALUE format)
{
    struct time_object *tobj;
    const char *fmt;
    long len;
    rb_encoding *enc;
    VALUE tmp;

    GetTimeval(time, tobj);
    MAKE_TM_ENSURE(time, tobj, tobj->vtm.yday != 0);
    StringValue(format);
    if (!rb_enc_str_asciicompat_p(format)) {
	rb_raise(rb_eArgError, "format should have ASCII compatible encoding");
    }
    tmp = rb_str_tmp_frozen_acquire(format);
    fmt = RSTRING_PTR(tmp);
    len = RSTRING_LEN(tmp);
    enc = rb_enc_get(format);
    if (len == 0) {
	rb_warning("strftime called with empty format string");
	return rb_enc_str_new(0, 0, enc);
    }
    else {
        VALUE str = rb_strftime_alloc(fmt, len, enc, time, &tobj->vtm, tobj->timew,
				      TZMODE_UTC_P(tobj));
	rb_str_tmp_frozen_release(format, tmp);
	if (!str) rb_raise(rb_eArgError, "invalid format: %"PRIsVALUE, format);
	return str;
    }
}

#subsecNumeric

Returns the subsecond for time.

The return value can be a rational number.

t = Time.now        #=> 2020-07-20 15:40:26.867462289 +0900
t.subsec            #=> (867462289/1000000000)

t = Time.now        #=> 2020-07-20 15:40:50.313828595 +0900
t.subsec            #=> (62765719/200000000)

t = Time.new(2000,1,1,2,3,4) #=> 2000-01-01 02:03:04 +0900
t.subsec                     #=> 0

Time.new(2000,1,1,0,0,1/3r,"UTC").subsec #=> (1/3)
[ GitHub ]

  
# File 'time.c', line 3703

static VALUE
time_subsec(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    return quov(w2v(wmod(tobj->timew, WINT2FIXWV(TIME_SCALE))), INT2FIX(TIME_SCALE));
}

#to_aArray

Returns a ten-element array of values for time:

[sec, min, hour, day, month, year, wday, yday, isdst, zone]

See the individual methods for an explanation of the valid ranges of each value. The ten elements can be passed directly to .utc or .local to create a new Time object.

t = Time.now     #=> 2007-11-19 08:36:01 -0600
now = t.to_a     #=> [1, 36, 8, 19, 11, 2007, 1, 323, false, "CST"]
[ GitHub ]

  
# File 'time.c', line 4833

static VALUE
time_to_a(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM_ENSURE(time, tobj, tobj->vtm.yday != 0);
    return rb_ary_new3(10,
		    INT2FIX(tobj->vtm.sec),
		    INT2FIX(tobj->vtm.min),
		    INT2FIX(tobj->vtm.hour),
		    INT2FIX(tobj->vtm.mday),
		    INT2FIX(tobj->vtm.mon),
		    tobj->vtm.year,
		    INT2FIX(tobj->vtm.wday),
		    INT2FIX(tobj->vtm.yday),
		    tobj->vtm.isdst?Qtrue:Qfalse,
		    time_zone(time));
}

#to_fFloat

Returns the value of time as a floating point number of seconds since the Epoch. The return value approximate the exact value in the Time object because floating point numbers cannot represent all rational numbers exactly.

t = Time.now        #=> 2020-07-20 22:00:29.38740268 +0900
t.to_f              #=> 1595250029.3874028
t.to_i              #=> 1595250029

Note that IEEE 754 double is not accurate enough to represent the exact number of nanoseconds since the Epoch. (IEEE 754 double has 53bit mantissa. So it can represent exact number of nanoseconds only in 2 ** 53 / 1_000_000_000 / 60 / 60 / 24 = 104.2 days.) When Ruby uses a nanosecond-resolution clock function, such as clock_gettime of POSIX, to obtain the current time, to_f can lost information of a Time object created with .now.

[ GitHub ]

  
# File 'time.c', line 3583

static VALUE
time_to_f(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    return rb_Float(rb_time_unmagnify_to_float(tobj->timew));
}

#to_iInteger #tv_secInteger
Also known as: #tv_sec

Returns the value of time as an integer number of seconds since the Epoch.

If time contains subsecond, they are truncated.

t = Time.now        #=> 2020-07-21 01:41:29.746012609 +0900
t.to_i              #=> 1595263289
[ GitHub ]

  
# File 'time.c', line 3550

static VALUE
time_to_i(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    return w2v(wdiv(tobj->timew, WINT2FIXWV(TIME_SCALE)));
}

#to_rRational

Returns the value of time as a rational number of seconds since the Epoch.

t = Time.now      #=> 2020-07-20 22:03:45.212167333 +0900
t.to_r            #=> (1595250225212167333/1000000000)

This method is intended to be used to get an accurate value representing the seconds (including subsecond) since the Epoch.

[ GitHub ]

  
# File 'time.c', line 3606

static VALUE
time_to_r(VALUE time)
{
    struct time_object *tobj;
    VALUE v;

    GetTimeval(time, tobj);
    v = rb_time_unmagnify_to_rational(tobj->timew);
    if (!RB_TYPE_P(v, T_RATIONAL)) {
        v = rb_Rational1(v);
    }
    return v;
}

#to_sString

Returns a string representing time. Equivalent to calling #strftime with the appropriate format string.

t = Time.now
t.to_s                              #=> "2012-11-10 18:16:12 +0100"
t.strftime "%Y-%m-%d %H:%M:%S %z"   #=> "2012-11-10 18:16:12 +0100"

t.utc.to_s                          #=> "2012-11-10 17:16:12 UTC"
t.strftime "%Y-%m-%d %H:%M:%S UTC"  #=> "2012-11-10 17:16:12 UTC"
[ GitHub ]

  
# File 'time.c', line 4128

static VALUE
time_to_s(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    if (TZMODE_UTC_P(tobj))
        return strftimev("%Y-%m-%d %H:%M:%S UTC", time, rb_usascii_encoding());
    else
        return strftimev("%Y-%m-%d %H:%M:%S %z", time, rb_usascii_encoding());
}

#nsecInteger #tv_nsecInteger

Alias for #nsec.

#to_iInteger #tv_secInteger

Alias for #to_i.

#usecInteger #tv_usecInteger

Alias for #usec.

#usecInteger #tv_usecInteger
Also known as: #tv_usec

Returns the number of microseconds for the subsecond part of time. The result is a non-negative integer less than 10**6.

t = Time.now        #=> 2020-07-20 22:05:58.459785953 +0900
t.usec              #=> 459785

If time has fraction of microsecond (such as nanoseconds), it is truncated.

t = Time.new(2000,1,1,0,0,0.666_777_888_999r)
t.usec              #=> 666777

#subsec can be used to obtain the subsecond part exactly.

[ GitHub ]

  
# File 'time.c', line 3640

static VALUE
time_usec(VALUE time)
{
    struct time_object *tobj;
    wideval_t w, q, r;

    GetTimeval(time, tobj);

    w = wmod(tobj->timew, WINT2WV(TIME_SCALE));
    wmuldivmod(w, WINT2FIXWV(1000000), WINT2FIXWV(TIME_SCALE), &q, &r);
    return rb_to_int(w2v(q));
}

#gmtimeTime (readonly) #utcTime
Also known as: #gmtime

Converts time to UTC (GMT), modifying the receiver.

t = Time.now   #=> 2007-11-19 08:18:31 -0600
t.gmt?         #=> false
t.gmtime       #=> 2007-11-19 14:18:31 UTC
t.gmt?         #=> true

t = Time.now   #=> 2007-11-19 08:18:51 -0600
t.utc?         #=> false
t.utc          #=> 2007-11-19 14:18:51 UTC
t.utc?         #=> true
[ GitHub ]

  
# File 'time.c', line 3948

static VALUE
time_gmtime(VALUE time)
{
    struct time_object *tobj;
    struct vtm vtm;

    GetTimeval(time, tobj);
    if (TZMODE_UTC_P(tobj)) {
	if (tobj->tm_got)
	    return time;
    }
    else {
	time_modify(time);
    }

    vtm.zone = str_utc;
    GMTIMEW(tobj->timew, &vtm);
    tobj->vtm = vtm;

    tobj->tm_got = 1;
    TZMODE_SET_UTC(tobj);
    return time;
}

#gmt_offsetInteger #gmtoffInteger #utc_offsetInteger

Alias for #gmtoff.

#wdayInteger

Returns an integer representing the day of the week, 0..6, with Sunday == 0.

t = Time.now   #=> 2007-11-20 02:35:35 -0600
t.wday         #=> 2
t.sunday?      #=> false
t.monday?      #=> false
t.tuesday?     #=> true
t.wednesday?   #=> false
t.thursday?    #=> false
t.friday?      #=> false
t.saturday?    #=> false
[ GitHub ]

  
# File 'time.c', line 4567

static VALUE
time_wday(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM_ENSURE(time, tobj, tobj->vtm.wday != VTM_WDAY_INITVAL);
    return INT2FIX((int)tobj->vtm.wday);
}

#ydayInteger

Returns an integer representing the day of the year, 1..366.

t = Time.now   #=> 2007-11-19 08:32:31 -0600
t.yday         #=> 323
[ GitHub ]

  
# File 'time.c', line 4703

static VALUE
time_yday(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM_ENSURE(time, tobj, tobj->vtm.yday != 0);
    return INT2FIX(tobj->vtm.yday);
}

#yearInteger

Returns the year for time (including the century).

t = Time.now   #=> 2007-11-19 08:27:51 -0600
t.year         #=> 2007
[ GitHub ]

  
# File 'time.c', line 4539

static VALUE
time_year(VALUE time)
{
    struct time_object *tobj;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    return tobj->vtm.year;
}

#zoneString, Time

Returns the name of the time zone used for time. As of Ruby 1.8, returns “UTC” rather than “GMT” for UTC times.

t = Time.gm(2000, "jan", 1, 20, 15, 1)
t.zone   #=> "UTC"
t = Time.local(2000, "jan", 1, 20, 15, 1)
t.zone   #=> "CST"
[ GitHub ]

  
# File 'time.c', line 4764

static VALUE
time_zone(VALUE time)
{
    struct time_object *tobj;
    VALUE zone;

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);

    if (TZMODE_UTC_P(tobj)) {
	return rb_usascii_str_new_cstr("UTC");
    }
    zone = tobj->vtm.zone;
    if (NIL_P(zone))
        return Qnil;

    if (RB_TYPE_P(zone, T_STRING))
        zone = rb_str_dup(zone);
    return zone;
}