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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 fraction since the Epoch, January 1, 1970 00:00 UTC. Also see the library module Date. 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 fraction. 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 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 .gm, .local and .utc to infer GMT, local and UTC timezones instead of using the current system setting.

You can also create a new time using Time.at} which takes the number of seconds (or fraction of seconds) since the 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 and abbr 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 sub-second; it has attribute readers for the parts, e.g. #year, #month, and so on, and epoch time readers, #to_i. The sub-second 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.

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.

Similary, 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 anObject #<=> max is greater than zero, true otherwise.

#clamp

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 fractional seconds.

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

#sec may have fraction 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      #=> 2007-11-19 07:50:02 -0600
b = Time.new      #=> 2007-11-19 07:50:02 -0600
a == b            #=> false
"%.6f" % a.to_f   #=> "1195480202.282373"
"%.6f" % b.to_f   #=> "1195480202.283415"

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 2397

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) ⇒ 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

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. non-portable feature allows the offset to be negative on some systems.

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.

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
[ GitHub ]

  
# File 'time.c', line 2768

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 3425

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 .gm, but interprets the values in the local time zone.

Time.local(2000,"jan",1,20,15,1)   #=> 2000-01-01 20:15:01 -0600
[ GitHub ]

  
# File 'time.c', line 3459

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 2700

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 4643

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 4576

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

#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 4512

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 4592

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
[ GitHub ]

  
# File 'time.c', line 4496

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 4560

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
[ GitHub ]

  
# File 'time.c', line 4528

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
[ GitHub ]

  
# File 'time.c', line 4544

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

Instance Method Details

#+(numeric) ⇒ Time

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

t = Time.now         #=> 2007-11-19 08:22:21 -0600
t + (60 * 60 * 24)   #=> 2007-11-20 08:22:21 -0600
[ GitHub ]

  
# File 'time.c', line 4086

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

Difference — 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       #=> 2007-11-19 08:23:10 -0600
t2 = t + 2592000   #=> 2007-12-19 08:23:10 -0600
t2 - t             #=> 2592000.0
t2 - 2592000       #=> 2007-11-19 08:23:10 -0600
[ GitHub ]

  
# File 'time.c', line 4113

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, ...

Comparison—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 3648

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 5114

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 sub seconds 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.

require 'time'

t = Time.utc(2010,3,30, 5,43,25.0123456789r)
t.iso8601(10)          #=> "2010-03-30T05:43:25.0123456789Z"
t.ceil.iso8601(10)     #=> "2010-03-30T05:43:26.0000000000Z"
t.ceil(0).iso8601(10)  #=> "2010-03-30T05:43:26.0000000000Z"
t.ceil(1).iso8601(10)  #=> "2010-03-30T05:43:25.1000000000Z"
t.ceil(2).iso8601(10)  #=> "2010-03-30T05:43:25.0200000000Z"
t.ceil(3).iso8601(10)  #=> "2010-03-30T05:43:25.0130000000Z"
t.ceil(4).iso8601(10)  #=> "2010-03-30T05:43:25.0124000000Z"

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.4).ceil.iso8601(3)    #=> "2000-01-01T00:00:00.000Z"
(t + 0.9).ceil.iso8601(3)    #=> "2000-01-01T00:00:00.000Z"
(t + 1.4).ceil.iso8601(3)    #=> "2000-01-01T00:00:01.000Z"
(t + 1.9).ceil.iso8601(3)    #=> "2000-01-01T00:00:01.000Z"

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.123456789).ceil(4).iso8601(6)  #=> "1999-12-31T23:59:59.123500Z"
[ GitHub ]

  
# File 'time.c', line 4305

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);
    return time_add(tobj, time, subv(den, 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 4018

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..n) for time.

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

  
# File 'time.c', line 4399

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 and fractional seconds.

[ GitHub ]

  
# File 'time.c', line 3675

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 sub seconds 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.

require 'time'

t = Time.utc(2010,3,30, 5,43,25.123456789r)
t.iso8601(10)           #=> "2010-03-30T05:43:25.1234567890Z"
t.floor.iso8601(10)     #=> "2010-03-30T05:43:25.0000000000Z"
t.floor(0).iso8601(10)  #=> "2010-03-30T05:43:25.0000000000Z"
t.floor(1).iso8601(10)  #=> "2010-03-30T05:43:25.1000000000Z"
t.floor(2).iso8601(10)  #=> "2010-03-30T05:43:25.1200000000Z"
t.floor(3).iso8601(10)  #=> "2010-03-30T05:43:25.1230000000Z"
t.floor(4).iso8601(10)  #=> "2010-03-30T05:43:25.1234000000Z"

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.4).floor.iso8601(3)    #=> "1999-12-31T23:59:59.000Z"
(t + 0.9).floor.iso8601(3)    #=> "1999-12-31T23:59:59.000Z"
(t + 1.4).floor.iso8601(3)    #=> "2000-01-01T00:00:00.000Z"
(t + 1.9).floor.iso8601(3)    #=> "2000-01-01T00:00:00.000Z"

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.123456789).floor(4).iso8601(6)  #=> "1999-12-31T23:59:59.123400Z"
[ GitHub ]

  
# File 'time.c', line 4258

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 3990

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 3945

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.

#utc?Boolean #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 3706

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

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

#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 4705

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 3725

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 4377

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 3735

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 #to_sString

Alias for #to_s.

#isdstBoolean #dst?Boolean

Alias for #dst?.

#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 3829

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 5009

static VALUE
time_mdump(VALUE time)
{
    struct time_object *tobj;
    unsigned long p, s;
    char buf[8];
    int i;
    VALUE str;

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

    GetTimeval(time, tobj);

    gmtimew(tobj->timew, &vtm);

    if (FIXNUM_P(vtm.year)) {
        year = FIX2LONG(vtm.year);
        if (year < 1900 || 1900+0xffff < year)
            rb_raise(rb_eArgError, "year too %s to marshal: %ld UTC",
                     (year < 1900 ? "small" : "big"), year);
    }
    else {
        rb_raise(rb_eArgError, "year too %s to marshal: %"PRIsVALUE" UTC",
                 (le(vtm.year, INT2FIX(1900)) ? "small" : "big"), vtm.year);
    }

    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);
    }

    str = rb_str_new(buf, 8);
    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 5146

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;
    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, NULL, Qnil)));
    get_attr(zone, (zone = rb_rescue(validate_zone_name, zone, NULL, Qnil)));

#undef get_attr

    rb_copy_generic_ivar(time, str);

    StringValue(str);
    buf = (unsigned char *)RSTRING_PTR(str);
    if (RSTRING_LEN(str) != 8) {
	rb_raise(rb_eTypeError, "marshaled time format differ");
    }

    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);

	vtm.year = INT2FIX(((int)(p >> 14) & 0xffff) + 1900);
	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 = rb_fstring_lit("");

	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;
    }

    return time;
}

#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 4357

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 4421

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 time.

t = Time.now        #=> 2007-11-17 15:18:03 +0900
"%10.9f" % t.to_f   #=> "1195280283.536151409"
t.nsec              #=> 536151406

The lowest digits of #to_f and #nsec are different because IEEE 754 double is not accurate enough to represent the exact number of nanoseconds since the Epoch.

The more accurate value is returned by #nsec.

[ GitHub ]

  
# File 'time.c', line 3586

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 sub seconds 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.

require 'time'

t = Time.utc(2010,3,30, 5,43,25.123456789r)
t.iso8601(10)           #=> "2010-03-30T05:43:25.1234567890Z"
t.round.iso8601(10)     #=> "2010-03-30T05:43:25.0000000000Z"
t.round(0).iso8601(10)  #=> "2010-03-30T05:43:25.0000000000Z"
t.round(1).iso8601(10)  #=> "2010-03-30T05:43:25.1000000000Z"
t.round(2).iso8601(10)  #=> "2010-03-30T05:43:25.1200000000Z"
t.round(3).iso8601(10)  #=> "2010-03-30T05:43:25.1230000000Z"
t.round(4).iso8601(10)  #=> "2010-03-30T05:43:25.1235000000Z"

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.4).round.iso8601(3)    #=> "1999-12-31T23:59:59.000Z"
(t + 0.49).round.iso8601(3)   #=> "1999-12-31T23:59:59.000Z"
(t + 0.5).round.iso8601(3)    #=> "2000-01-01T00:00:00.000Z"
(t + 1.4).round.iso8601(3)    #=> "2000-01-01T00:00:00.000Z"
(t + 1.49).round.iso8601(3)   #=> "2000-01-01T00:00:00.000Z"
(t + 1.5).round.iso8601(3)    #=> "2000-01-01T00:00:01.000Z"

t = Time.utc(1999,12,31, 23,59,59)
(t + 0.123456789).round(4).iso8601(6)  #=> "1999-12-31T23:59:59.123500Z"
[ GitHub ]

  
# File 'time.c', line 4208

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 4337

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 4976

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(time, tobj);
    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 fraction for time.

The return value can be a rational number.

t = Time.now        #=> 2009-03-26 22:33:12 +0900
"%10.9f" % t.to_f   #=> "1238074392.940563917"
t.subsec            #=> (94056401/100000000)

The lowest digits of #to_f and #subsec are different because IEEE 754 double is not accurate enough to represent the rational number.

The more accurate value is returned by #subsec.

[ GitHub ]

  
# File 'time.c', line 3614

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));
}

#succTime

Returns a new Time object, one second later than time. succ is obsolete since 1.9.2 for time is not a discrete value.

t = Time.now       #=> 2007-11-19 08:23:57 -0600
t.succ             #=> 2007-11-19 08:23:58 -0600

Use instead time + 1

t + 1              #=> 2007-11-19 08:23:58 -0600
[ GitHub ]

  
# File 'time.c', line 4143

VALUE
rb_time_succ(VALUE time)
{
    struct time_object *tobj;
    struct time_object *tobj2;

    rb_warn("Time#succ is obsolete; use time + 1");
    GetTimeval(time, tobj);
    time = time_new_timew(rb_cTime, wadd(tobj->timew, WINT2FIXWV(TIME_SCALE)));
    GetTimeval(time, tobj2);
    TZMODE_COPY(tobj2, tobj);
    if (TZMODE_LOCALTIME_P(tobj2) && maybe_tzobj_p(tobj2->vtm.zone)) {
        zone_localtime(tobj2->vtm.zone, time);
    }
    return time;
}

#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 4738

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

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

t = Time.now
"%10.5f" % t.to_f   #=> "1270968744.77658"
t.to_i              #=> 1270968744

Note that IEEE 754 double is not accurate enough to represent the exact number of nanoseconds since the Epoch.

[ GitHub ]

  
# File 'time.c', line 3505

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.

t = Time.now
"%10.5f" % t.to_f   #=> "1270968656.89607"
t.to_i              #=> 1270968656
[ GitHub ]

  
# File 'time.c', line 3481

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
t.to_r            #=> (1270968792716287611/1000000000)

This methods is intended to be used to get an accurate value representing the nanoseconds since the Epoch. You can use this method to convert time to another Epoch.

[ GitHub ]

  
# File 'time.c', line 3529

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

    GetTimeval(time, tobj);
    v = w2v(rb_time_unmagnify(tobj->timew));
    if (!RB_TYPE_P(v, T_RATIONAL)) {
        v = rb_Rational1(v);
    }
    return v;
}

#inspectString #to_sString
Also known as: #inspect

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 4040

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 time.

t = Time.now        #=> 2007-11-19 08:03:26 -0600
"%10.6f" % t.to_f   #=> "1195481006.775195"
t.usec              #=> 775195
[ GitHub ]

  
# File 'time.c', line 3555

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 3859

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 = rb_fstring_lit("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 4469

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

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    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 4608

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

    GetTimeval(time, tobj);
    MAKE_TM(time, tobj);
    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 4441

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 4669

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;
}