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author | Nobuyoshi Nakada <nobu@ruby-lang.org> | 2021-06-06 12:08:54 +0900 |
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committer | Nobuyoshi Nakada <nobu@ruby-lang.org> | 2021-06-07 20:44:05 +0900 |
commit | c741ea0be7402fd709207548d78b044fb89dffd0 (patch) | |
tree | 30838c23514ac918f83932de608e24689abe53c1 /timev.rb | |
parent | 4bd538e847c9e9b106ebd2bab9bb5075ffb8014d (diff) |
timev.rb: moved class rdoc from time.c
Diffstat (limited to 'timev.rb')
-rw-r--r-- | timev.rb | 208 |
1 files changed, 208 insertions, 0 deletions
@@ -1,3 +1,211 @@ +# Time is an abstraction of dates and times. Time is stored internally as +# the number of seconds with subsecond since the _Epoch_, +# 1970-01-01 00:00:00 UTC. +# +# The Time class treats GMT +# (Greenwich Mean Time) and UTC (Coordinated Universal Time) as equivalent. +# GMT is the older way of referring to these baseline times but persists in +# the names of calls on POSIX systems. +# +# 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.) +# +# == 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 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 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: +# +# 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 +# Epoch}[https://en.wikipedia.org/wiki/Unix_time]. +# +# 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 +# +# \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 object}[#class-Time-label-Methods+for+Converting]. +# - {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 seconds. +# - {-}[#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 1). +# - #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 time. +# - #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 saving time). +# - #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 format. +# - #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 defined. +# +# Similarly, that class method will be called when a timezone argument does +# not have the necessary methods mentioned above. class Time # Creates a new \Time object from the current system time. # This is the same as Time.new without arguments. |