# Time < Object
Comparable (from ruby core)
(from ruby core)
Time is an abstraction of dates and times. Time is stored internally as
the number of seconds with subsecond since the *Epoch*, 1970-01-01
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
Note: A Time object uses the resolution available on your system clock.
All times may have subsecond. Be aware of this fact when comparing times
with each other -- times that are apparently equal when displayed may be
different when compared. (Since Ruby 2.7.0, Time#inspect shows subsecond
but Time#to_s still doesn't show subsecond.)
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 Time.new. This will use the
current system time. Time.now is an alias for this. You can also pass
parts of the time to Time.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
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:
zone = timezone("Europe/Athens") # Eastern European Time, UTC+2
Time.new(2002, 10, 31, 2, 2, 2, zone) #=> 2002-10-31 02:02:02 +0200
You can also use Time.local and Time.utc to infer 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 (with subsecond) since the [Unix
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
## What's Here
First, what's elsewhere. Class Time:
* Inherits from [class
* Includes [module
Here, class Time provides methods that are useful for:
* [Creating \Time objects](#class-Time-label-Methods+for+Creating).
* [Fetching \Time values](#class-Time-label-Methods+for+Fetching).
* [Querying a \Time object](#class-Time-label-Methods+for+Querying).
* [Comparing \Time objects](#class-Time-label-Methods+for+Comparing).
* [Converting a \Time
* [Rounding a \Time](#class-Time-label-Methods+for+Rounding).
### Methods for Creating
* ::new: Returns a new time from specified arguments (year, month,
etc.), including an optional timezone value.
* ::local (aliased as ::mktime): Same as ::new, except the timezone is
the local timezone.
* ::utc (aliased as ::gm): Same as ::new, except the timezone is UTC.
* ::at: Returns a new time based on seconds since epoch.
* ::now: Returns a new time based on the current system time.
* #+ (plus): Returns a new time increased by the given number of
* [-](#method-i-2D) (minus): Returns a new time
decreased by the given number of seconds.
### Methods for Fetching
* #year: Returns the year of the time.
* #month (aliased as #mon): Returns the month of the time.
* #mday (aliased as #day): Returns the day of the month.
* #hour: Returns the hours value for the time.
* #min: Returns the minutes value for the time.
* #sec: Returns the seconds value for the time.
* #usec (aliased as #tv_usec): Returns the number of microseconds in
the subseconds value of the time.
* #nsec (aliased as #tv_nsec: Returns the number of nanoseconds in the
subsecond part of the time.
* #subsec: Returns the subseconds value for the time.
* #wday: Returns the integer weekday value of the time (0 == Sunday).
* #yday: Returns the integer yearday value of the time (1 == January
* #hash: Returns the integer hash value for the time.
* #utc_offset (aliased as #gmt_offset and #gmtoff): Returns the offset
in seconds between time and UTC.
* #to_f: Returns the float number of seconds since epoch for the time.
* #to_i (aliased as #tv_sec): Returns the integer number of seconds
since epoch for the time.
* #to_r: Returns the Rational number of seconds since epoch for the
* #zone: Returns a string representation of the timezone of the time.
### Methods for Querying
* #utc? (aliased as #gmt?): Returns whether the time is UTC.
* #dst? (aliased as #isdst): Returns whether the time is DST (daylight
* #sunday?: Returns whether the time is a Sunday.
* #monday?: Returns whether the time is a Monday.
* #tuesday?: Returns whether the time is a Tuesday.
* #wednesday?: Returns whether the time is a Wednesday.
* #thursday?: Returns whether the time is a Thursday.
* #friday?: Returns whether time is a Friday.
* #saturday?: Returns whether the time is a Saturday.
### Methods for Comparing
* [#<=>](#method-i-3C-3D-3E): Compares `self` to another time.
* #eql?: Returns whether the time is equal to another time.
### Methods for Converting
* #asctime (aliased as #ctime): Returns the time as a string.
* #inspect: Returns the time in detail as a string.
* #strftime: Returns the time as a string, according to a given
* #to_a: Returns a 10-element array of values from the time.
* #to_s: Returns a string representation of the time.
* #getutc (aliased as #getgm): Returns a new time converted to UTC.
* #getlocal: Returns a new time converted to local time.
* #utc (aliased as #gmtime): Converts time to UTC in place.
* #localtime: Converts time to local time in place.
### Methods for Rounding
* #round:Returns a new time with subseconds rounded.
* #ceil: Returns a new time with subseconds raised to a ceiling.
* #floor: Returns a new time with subseconds lowered to a floor.
## Timezone Argument
A timezone argument must have `local_to_utc` and `utc_to_local` methods,
and may have `name`, `abbr`, and `dst?` methods.
The `local_to_utc` method should convert a Time-like object from the
timezone to UTC, and `utc_to_local` is the opposite. The result also
should be a Time or Time-like object (not necessary to be the same
class). The #zone of the result is just ignored. Time-like argument to
these methods is similar to a Time object in UTC without subsecond; it
has attribute readers for the parts, e.g. #year, #month, and so on, and
epoch time readers, #to_i. The subsecond attributes are fixed as 0, and
#utc_offset, #zone, #isdst, and their aliases are same as a Time object
in UTC. Also #to_time, #+, and #- methods are defined.
The `name` method is used for marshaling. If this method is not defined
on a timezone object, Time objects using that timezone object can not be
dumped by Marshal.
The `abbr` method is used by '%Z' in #strftime.
The `dst?` method is called with a `Time` value and should return
whether the `Time` value is in daylight savings time in the zone.
### Auto Conversion to Timezone
At loading marshaled data, a timezone name will be converted to a
timezone object by `find_timezone` class method, if the method is
Similarly, that class method will be called when a timezone argument
does not have the necessary methods mentioned above.
# Class methods:
# Instance methods: