class Time

Time

This form accepts a Time object time and optional keyword argument in:

Time.at(Time.new)               # => 2021-04-26 08:52:31.6023486 -0500
Time.at(Time.new, in: '+09:00') # => 2021-04-26 22:52:31.6023486 +0900

Seconds

This form accepts a numeric number of seconds sec and optional keyword argument in:

Time.at(946702800)               # => 1999-12-31 23:00:00 -0600
Time.at(946702800, in: '+09:00') # => 2000-01-01 14:00:00 +0900

Seconds with Subseconds and Units

This form accepts an integer number of seconds sec_i, a numeric number of milliseconds msec, a symbol argument for the subsecond unit type (defaulting to :usec), and an optional keyword argument in:

Time.at(946702800, 500, :millisecond)               # => 1999-12-31 23:00:00.5 -0600
Time.at(946702800, 500, :millisecond, in: '+09:00') # => 2000-01-01 14:00:00.5 +0900
Time.at(946702800, 500000)                             # => 1999-12-31 23:00:00.5 -0600
Time.at(946702800, 500000, :usec)                      # => 1999-12-31 23:00:00.5 -0600
Time.at(946702800, 500000, :microsecond)               # => 1999-12-31 23:00:00.5 -0600
Time.at(946702800, 500000, in: '+09:00')               # => 2000-01-01 14:00:00.5 +0900
Time.at(946702800, 500000, :usec, in: '+09:00')        # => 2000-01-01 14:00:00.5 +0900
Time.at(946702800, 500000, :microsecond, in: '+09:00') # => 2000-01-01 14:00:00.5 +0900
Time.at(946702800, 500000000, :nsec)                     # => 1999-12-31 23:00:00.5 -0600
Time.at(946702800, 500000000, :nanosecond)               # => 1999-12-31 23:00:00.5 -0600
Time.at(946702800, 500000000, :nsec, in: '+09:00')       # => 2000-01-01 14:00:00.5 +0900
Time.at(946702800, 500000000, :nanosecond, in: '+09:00') # => 2000-01-01 14:00:00.5 +0900

Parameters:

• isec_i is the integer number of seconds in the range 0..60.

• msec is the number of milliseconds (Integer, Float, or Rational) in the range 0..1000.

• usec is the number of microseconds (Integer, Float, or Rational) in the range 0..1000000.

• nsec is the number of nanoseconds (Integer, Float, or Rational) in the range 0..1000000000.

• in: zone: a timezone zone, which may be:

  • A string offset from UTC.

  • A single letter offset from UTC, in the range 'A'..'Z', 'J' (the so-called military timezone) excluded.

  • An integer number of seconds.

  • A timezone object; see Timezone Argument for details.

# File ruby_3_1_5/timev.rb, line 270
def self.at(time, subsec = false, unit = :microsecond, in: nil)
  if Primitive.mandatory_only?
    Primitive.time_s_at1(time)
  else
    Primitive.time_s_at(time, subsec, unit, Primitive.arg!(:in))
  end
end

Returns a new Time object based the on given arguments; its timezone is the local timezone.

In the first form (up to seven arguments), argument year is required.

Time.local(2000)                   # => 2000-01-01 00:00:00 -0600
Time.local(0, 1, 2, 3, 4, 5, 6.5)  # => 0000-01-02 03:04:05.0000065 -0600

In the second form, all ten arguments are required, though the last four are ignored. This form is useful for creating a time from a 10-element array such as those returned by to_a.

array = Time.now.to_a
p array # => [57, 26, 13, 24, 4, 2021, 6, 114, true, "Central Daylight Time"]
array[5] = 2000
Time.local(*array)  # => 2000-04-24 13:26:57 -0500

Parameters:

• year: an integer year.

• month: a month value, which may be:

  • An integer month in the range 1..12.

  • A 3-character string that matches regular expression /jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec/i.

• day: an integer day in the range 1..31 (less than 31 for some months).

• hour: an integer hour in the range 0..23.

• min: an integer minute in the range 0..59.

• isec_i is the integer number of seconds in the range 0..60.

• usec is the number of microseconds (Integer, Float, or Rational) in the range 0..1000000.

Alias: Time.mktime.

Related: Time.utc.

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)));
}

Returns a new Time object based on the given arguments.

With no positional arguments, returns the value of Time.now:

Time.new                                       # => 2021-04-24 17:27:46.0512465 -0500

Otherwise, returns a new Time object based on the given parameters:

Time.new(2000)                                 # => 2000-01-01 00:00:00 -0600
Time.new(2000, 12, 31, 23, 59, 59.5)           # => 2000-12-31 23:59:59.5 -0600
Time.new(2000, 12, 31, 23, 59, 59.5, '+09:00') # => 2000-12-31 23:59:59.5 +0900

Parameters:

• year: an integer year.

• month: a month value, which may be:

  • An integer month in the range 1..12.

  • A 3-character string that matches regular expression /jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec/i.

• day: an integer day in the range 1..31 (less than 31 for some months).

• hour: an integer hour in the range 0..23.

• min: an integer minute in the range 0..59.

• sec is the number of seconds (Integer, Float, or Rational) in the range 0..60.

• zone: a timezone, which may be:

  • A string offset from UTC.

  • A single letter offset from UTC, in the range 'A'..'Z', 'J' (the so-called military timezone) excluded.

  • An integer number of seconds.

  • A timezone object; see Timezone Argument for details.

• in: zone: a timezone zone, which may be as above.

# File ruby_3_1_5/timev.rb, line 297
def initialize(year = (now = true), mon = nil, mday = nil, hour = nil, min = nil, sec = nil, zone = nil, in: nil)
  if zone
    if Primitive.arg!(:in)
      raise ArgumentError, "timezone argument given as positional and keyword arguments"
    end
  else
    zone = Primitive.arg!(:in)
  end

  if now
    return Primitive.time_init_now(zone)
  end

  Primitive.time_init_args(year, mon, mday, hour, min, sec, zone)
end

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

Time.now               # => 2009-06-24 12:39:54 +0900
Time.now(in: '+04:00') # => 2009-06-24 07:39:54 +0400

Parameter:

• in: zone: a timezone zone, which may be:

  • A string offset from UTC.

  • A single letter offset from UTC, in the range 'A'..'Z', 'J' (the so-called military timezone) excluded.

  • An integer number of seconds.

  • A timezone object; see Timezone Argument for details.

# File ruby_3_1_5/timev.rb, line 223
def self.now(in: nil)
  new(in: Primitive.arg!(:in))
end

Returns a new Time object based the on given arguments; its timezone is UTC.

In the first form (up to seven arguments), argument year is required.

Time.utc(2000)                  # => 2000-01-01 00:00:00 UTC
Time.utc(0, 1, 2, 3, 4, 5, 6.5) # => 0000-01-02 03:04:05.0000065 UTC

In the second form, all ten arguments are required, though the last four are ignored. This form is useful for creating a time from a 10-element array such as is returned by to_a.

array = Time.now.to_a
p array # => [57, 26, 13, 24, 4, 2021, 6, 114, true, "Central Daylight Time"]
array[5] = 2000
Time.utc(*array) # => 2000-04-24 13:26:57 UTC

Parameters:

• year: an integer year.

• month: a month value, which may be:

  • An integer month in the range 1..12.

  • A 3-character string that matches regular expression /jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec/i.

• day: an integer day in the range 1..31 (less than 31 for some months).

• hour: an integer hour in the range 0..23.

• min: an integer minute in the range 0..59.

• isec_i is the integer number of seconds in the range 0..60.

• usec is the number of microseconds (Integer, Float, or Rational) in the range 0..1000000.

Alias: Time.gm.

Related: Time.local.

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)));
}

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

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);
}

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

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);
}

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

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);
}

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

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);
}

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"

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

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

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;
}

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

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);
}

Returns true if time represents Friday.

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

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

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

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

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))) {
            off = zone;
            if (NIL_P(zone = find_timezone(time, off))) invalid_utc_offset(off);
            time = time_dup(time);
            if (!zone_localtime(zone, time)) invalid_utc_offset(off);
            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));
}

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

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;
}

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

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;
    }
}

Returns a hash code for this Time object.

See also Object#hash.

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

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

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

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

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

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

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"

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 (subsec == INT2FIX(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 {
        /* ?TODO: subsecond offset */
        long off = NUM2LONG(rb_funcall(tobj->vtm.utc_offset, rb_intern("round"), 0));
        char sign = (off < 0) ? (off = -off, '-') : '+';
        int sec = off % 60;
        int min = (off /= 60) % 60;
        off /= 60;
        rb_str_catf(str, " %c%.2d%.2d", sign, (int)off, min);
        if (sec) rb_str_catf(str, "%.2d", sec);
    }
    return str;
}

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

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 RBOOL(tobj->vtm.isdst);
}

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.

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);
}

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

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

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

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

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

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

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

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

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

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

Returns true if time represents Monday.

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

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

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

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);
}

Returns true if time represents Saturday.

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

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

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

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

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

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)

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;
    }
}

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)

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));
}

Returns true if time represents Sunday.

t = Time.local(1990, 4, 1)       #=> 1990-04-01 00:00:00 -0600
t.sunday?                        #=> true

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

Returns true if time represents Thursday.

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

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

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 Time.utc or Time.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"]

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),
                    RBOOL(tobj->vtm.isdst),
                    time_zone(time));
}

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, Time#to_f can lose information of a Time object created with Time.now.

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

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

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

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

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

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.

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;
}

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"

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());
}

Returns true if time represents Tuesday.

t = Time.local(1991, 2, 19)      #=> 1991-02-19 00:00:00 -0600
t.tuesday?                       #=> true

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

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

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

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)));
}

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

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

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));
}

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

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

    GetTimeval(time, tobj);
    return RBOOL(TZMODE_UTC_P(tobj));
}

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

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);
}

Returns true if time represents Wednesday.

t = Time.local(1993, 2, 24)      #=> 1993-02-24 00:00:00 -0600
t.wednesday?                     #=> true

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

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

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

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);
}

Returns the year for time (including the century).

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

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

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

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"

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;
}