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ruby--ruby/lib/time.rb
zzak ea418dda41 * time.c: [DOC] Clarify %Y in strftime, which can accept any digits
and will output at least 4 digits as the year. Reported by Yury
  Trofimenko [Bug #8941]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46982 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2014-07-27 20:58:05 +00:00

676 lines
22 KiB
Ruby

require 'date'
# = time.rb
#
# When 'time' is required, Time is extended with additional methods for parsing
# and converting Times.
#
# == Features
#
# This library extends the Time class with the following conversions between
# date strings and Time objects:
#
# * date-time defined by {RFC 2822}[http://www.ietf.org/rfc/rfc2822.txt]
# * HTTP-date defined by {RFC 2616}[http://www.ietf.org/rfc/rfc2616.txt]
# * dateTime defined by XML Schema Part 2: Datatypes ({ISO
# 8601}[http://www.iso.org/iso/date_and_time_format])
# * various formats handled by Date._parse
# * custom formats handled by Date._strptime
#
# == Examples
#
# All examples assume you have loaded Time with:
#
# require 'time'
#
# All of these examples were done using the EST timezone which is GMT-5.
#
# === Converting to a String
#
# t = Time.now
# t.iso8601 # => "2011-10-05T22:26:12-04:00"
# t.rfc2822 # => "Wed, 05 Oct 2011 22:26:12 -0400"
# t.httpdate # => "Thu, 06 Oct 2011 02:26:12 GMT"
#
# === Time.parse
#
# #parse takes a string representation of a Time and attempts to parse it
# using a heuristic.
#
# Date.parse("2010-10-31") #=> 2010-10-31 00:00:00 -0500
#
# Any missing pieces of the date are inferred based on the current date.
#
# # assuming the current date is "2011-10-31"
# Time.parse("12:00") #=> 2011-10-31 12:00:00 -0500
#
# We can change the date used to infer our missing elements by passing a second
# object that responds to #mon, #day and #year, such as Date, Time or DateTime.
# We can also use our own object.
#
# class MyDate
# attr_reader :mon, :day, :year
#
# def initialize(mon, day, year)
# @mon, @day, @year = mon, day, year
# end
# end
#
# d = Date.parse("2010-10-28")
# t = Time.parse("2010-10-29")
# dt = DateTime.parse("2010-10-30")
# md = MyDate.new(10,31,2010)
#
# Time.parse("12:00", d) #=> 2010-10-28 12:00:00 -0500
# Time.parse("12:00", t) #=> 2010-10-29 12:00:00 -0500
# Time.parse("12:00", dt) #=> 2010-10-30 12:00:00 -0500
# Time.parse("12:00", md) #=> 2010-10-31 12:00:00 -0500
#
# #parse also accepts an optional block. You can use this block to specify how
# to handle the year component of the date. This is specifically designed for
# handling two digit years. For example, if you wanted to treat all two digit
# years prior to 70 as the year 2000+ you could write this:
#
# Time.parse("01-10-31") {|year| year + (year < 70 ? 2000 : 1900)}
# #=> 2001-10-31 00:00:00 -0500
# Time.parse("70-10-31") {|year| year + (year < 70 ? 2000 : 1900)}
# #=> 1970-10-31 00:00:00 -0500
#
# === Time.strptime
#
# #strptime works similar to +parse+ except that instead of using a heuristic
# to detect the format of the input string, you provide a second argument that
# describes the format of the string. For example:
#
# Time.strptime("2000-10-31", "%Y-%m-%d") #=> 2000-10-31 00:00:00 -0500
class Time
class << Time
#
# A hash of timezones mapped to hour differences from UTC. The
# set of time zones corresponds to the ones specified by RFC 2822
# and ISO 8601.
#
ZoneOffset = { # :nodoc:
'UTC' => 0,
# ISO 8601
'Z' => 0,
# RFC 822
'UT' => 0, 'GMT' => 0,
'EST' => -5, 'EDT' => -4,
'CST' => -6, 'CDT' => -5,
'MST' => -7, 'MDT' => -6,
'PST' => -8, 'PDT' => -7,
# Following definition of military zones is original one.
# See RFC 1123 and RFC 2822 for the error in RFC 822.
'A' => +1, 'B' => +2, 'C' => +3, 'D' => +4, 'E' => +5, 'F' => +6,
'G' => +7, 'H' => +8, 'I' => +9, 'K' => +10, 'L' => +11, 'M' => +12,
'N' => -1, 'O' => -2, 'P' => -3, 'Q' => -4, 'R' => -5, 'S' => -6,
'T' => -7, 'U' => -8, 'V' => -9, 'W' => -10, 'X' => -11, 'Y' => -12,
}
#
# Return the number of seconds the specified time zone differs
# from UTC.
#
# Numeric time zones that include minutes, such as
# <code>-10:00</code> or <code>+1330</code> will work, as will
# simpler hour-only time zones like <code>-10</code> or
# <code>+13</code>.
#
# Textual time zones listed in ZoneOffset are also supported.
#
# If the time zone does not match any of the above, +zone_offset+
# will check if the local time zone (both with and without
# potential Daylight Saving \Time changes being in effect) matches
# +zone+. Specifying a value for +year+ will change the year used
# to find the local time zone.
#
# If +zone_offset+ is unable to determine the offset, nil will be
# returned.
def zone_offset(zone, year=self.now.year)
off = nil
zone = zone.upcase
if /\A([+-])(\d\d):?(\d\d)\z/ =~ zone
off = ($1 == '-' ? -1 : 1) * ($2.to_i * 60 + $3.to_i) * 60
elsif /\A[+-]\d\d\z/ =~ zone
off = zone.to_i * 3600
elsif ZoneOffset.include?(zone)
off = ZoneOffset[zone] * 3600
elsif ((t = self.local(year, 1, 1)).zone.upcase == zone rescue false)
off = t.utc_offset
elsif ((t = self.local(year, 7, 1)).zone.upcase == zone rescue false)
off = t.utc_offset
end
off
end
def zone_utc?(zone)
# * +0000
# In RFC 2822, +0000 indicate a time zone at Universal Time.
# Europe/Lisbon is "a time zone at Universal Time" in Winter.
# Atlantic/Reykjavik is "a time zone at Universal Time".
# Africa/Dakar is "a time zone at Universal Time".
# So +0000 is a local time such as Europe/London, etc.
# * GMT
# GMT is used as a time zone abbreviation in Europe/London,
# Africa/Dakar, etc.
# So it is a local time.
#
# * -0000, -00:00
# In RFC 2822, -0000 the date-time contains no information about the
# local time zone.
# In RFC 3339, -00:00 is used for the time in UTC is known,
# but the offset to local time is unknown.
# They are not appropriate for specific time zone such as
# Europe/London because time zone neutral,
# So -00:00 and -0000 are treated as UTC.
if /\A(?:-00:00|-0000|-00|UTC|Z|UT)\z/i =~ zone
true
else
false
end
end
private :zone_utc?
def force_zone!(t, zone, offset=nil)
if zone_utc?(zone)
t.utc
elsif offset ||= zone_offset(zone)
# Prefer the local timezone over the fixed offset timezone because
# the former is a real timezone and latter is an artificial timezone.
t.localtime
if t.utc_offset != offset
# Use the fixed offset timezone only if the local timezone cannot
# represent the given offset.
t.localtime(offset)
end
else
t.localtime
end
end
private :force_zone!
LeapYearMonthDays = [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] # :nodoc:
CommonYearMonthDays = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31] # :nodoc:
def month_days(y, m)
if ((y % 4 == 0) && (y % 100 != 0)) || (y % 400 == 0)
LeapYearMonthDays[m-1]
else
CommonYearMonthDays[m-1]
end
end
private :month_days
def apply_offset(year, mon, day, hour, min, sec, off)
if off < 0
off = -off
off, o = off.divmod(60)
if o != 0 then sec += o; o, sec = sec.divmod(60); off += o end
off, o = off.divmod(60)
if o != 0 then min += o; o, min = min.divmod(60); off += o end
off, o = off.divmod(24)
if o != 0 then hour += o; o, hour = hour.divmod(24); off += o end
if off != 0
day += off
days = month_days(year, mon)
if days and days < day
mon += 1
if 12 < mon
mon = 1
year += 1
end
day = 1
end
end
elsif 0 < off
off, o = off.divmod(60)
if o != 0 then sec -= o; o, sec = sec.divmod(60); off -= o end
off, o = off.divmod(60)
if o != 0 then min -= o; o, min = min.divmod(60); off -= o end
off, o = off.divmod(24)
if o != 0 then hour -= o; o, hour = hour.divmod(24); off -= o end
if off != 0 then
day -= off
if day < 1
mon -= 1
if mon < 1
year -= 1
mon = 12
end
day = month_days(year, mon)
end
end
end
return year, mon, day, hour, min, sec
end
private :apply_offset
def make_time(date, year, mon, day, hour, min, sec, sec_fraction, zone, now)
if !year && !mon && !day && !hour && !min && !sec && !sec_fraction
raise ArgumentError, "no time information in #{date.inspect}"
end
off_year = year || now.year
off = nil
off = zone_offset(zone, off_year) if zone
if off
now = now.getlocal(off) if now.utc_offset != off
else
now = now.getlocal
end
usec = nil
usec = sec_fraction * 1000000 if sec_fraction
if now
begin
break if year; year = now.year
break if mon; mon = now.mon
break if day; day = now.day
break if hour; hour = now.hour
break if min; min = now.min
break if sec; sec = now.sec
break if sec_fraction; usec = now.tv_usec
end until true
end
year ||= 1970
mon ||= 1
day ||= 1
hour ||= 0
min ||= 0
sec ||= 0
usec ||= 0
if year != off_year
off = nil
off = zone_offset(zone, year) if zone
end
if off
year, mon, day, hour, min, sec =
apply_offset(year, mon, day, hour, min, sec, off)
t = self.utc(year, mon, day, hour, min, sec, usec)
force_zone!(t, zone, off)
t
else
self.local(year, mon, day, hour, min, sec, usec)
end
end
private :make_time
#
# Parses +date+ using Date._parse and converts it to a Time object.
#
# If a block is given, the year described in +date+ is converted by the
# block. For example:
#
# Time.parse(...) {|y| 0 <= y && y < 100 ? (y >= 69 ? y + 1900 : y + 2000) : y}
#
# If the upper components of the given time are broken or missing, they are
# supplied with those of +now+. For the lower components, the minimum
# values (1 or 0) are assumed if broken or missing. For example:
#
# # Suppose it is "Thu Nov 29 14:33:20 2001" now and
# # your time zone is EST which is GMT-5.
# now = Time.parse("Thu Nov 29 14:33:20 2001")
# Time.parse("16:30", now) #=> 2001-11-29 16:30:00 -0500
# Time.parse("7/23", now) #=> 2001-07-23 00:00:00 -0500
# Time.parse("Aug 31", now) #=> 2001-08-31 00:00:00 -0500
# Time.parse("Aug 2000", now) #=> 2000-08-01 00:00:00 -0500
#
# Since there are numerous conflicts among locally defined time zone
# abbreviations all over the world, this method is not intended to
# understand all of them. For example, the abbreviation "CST" is
# used variously as:
#
# -06:00 in America/Chicago,
# -05:00 in America/Havana,
# +08:00 in Asia/Harbin,
# +09:30 in Australia/Darwin,
# +10:30 in Australia/Adelaide,
# etc.
#
# Based on this fact, this method only understands the time zone
# abbreviations described in RFC 822 and the system time zone, in the
# order named. (i.e. a definition in RFC 822 overrides the system
# time zone definition.) The system time zone is taken from
# <tt>Time.local(year, 1, 1).zone</tt> and
# <tt>Time.local(year, 7, 1).zone</tt>.
# If the extracted time zone abbreviation does not match any of them,
# it is ignored and the given time is regarded as a local time.
#
# ArgumentError is raised if Date._parse cannot extract information from
# +date+ or if the Time class cannot represent specified date.
#
# This method can be used as a fail-safe for other parsing methods as:
#
# Time.rfc2822(date) rescue Time.parse(date)
# Time.httpdate(date) rescue Time.parse(date)
# Time.xmlschema(date) rescue Time.parse(date)
#
# A failure of Time.parse should be checked, though.
#
# You must require 'time' to use this method.
#
def parse(date, now=self.now)
comp = !block_given?
d = Date._parse(date, comp)
year = d[:year]
year = yield(year) if year && !comp
make_time(date, year, d[:mon], d[:mday], d[:hour], d[:min], d[:sec], d[:sec_fraction], d[:zone], now)
end
#
# Parses +date+ using Date._strptime and converts it to a Time object.
#
# If a block is given, the year described in +date+ is converted by the
# block. For example:
#
# Time.strptime(...) {|y| y < 100 ? (y >= 69 ? y + 1900 : y + 2000) : y}
#
# Below is a list of the formatting options:
#
# %a :: The abbreviated weekday name ("Sun")
# %A :: The full weekday name ("Sunday")
# %b :: The abbreviated month name ("Jan")
# %B :: The full month name ("January")
# %c :: The preferred local date and time representation
# %C :: Century (20 in 2009)
# %d :: Day of the month (01..31)
# %D :: Date (%m/%d/%y)
# %e :: Day of the month, blank-padded ( 1..31)
# %F :: Equivalent to %Y-%m-%d (the ISO 8601 date format)
# %h :: Equivalent to %b
# %H :: Hour of the day, 24-hour clock (00..23)
# %I :: Hour of the day, 12-hour clock (01..12)
# %j :: Day of the year (001..366)
# %k :: hour, 24-hour clock, blank-padded ( 0..23)
# %l :: hour, 12-hour clock, blank-padded ( 0..12)
# %L :: Millisecond of the second (000..999)
# %m :: Month of the year (01..12)
# %M :: Minute of the hour (00..59)
# %n :: Newline (\n)
# %N :: Fractional seconds digits, default is 9 digits (nanosecond)
# %3N :: millisecond (3 digits)
# %6N :: microsecond (6 digits)
# %9N :: nanosecond (9 digits)
# %p :: Meridian indicator ("AM" or "PM")
# %P :: Meridian indicator ("am" or "pm")
# %r :: time, 12-hour (same as %I:%M:%S %p)
# %R :: time, 24-hour (%H:%M)
# %s :: Number of seconds since 1970-01-01 00:00:00 UTC.
# %S :: Second of the minute (00..60)
# %t :: Tab character (\t)
# %T :: time, 24-hour (%H:%M:%S)
# %u :: Day of the week as a decimal, Monday being 1. (1..7)
# %U :: Week number of the current year, starting with the first Sunday as
# the first day of the first week (00..53)
# %v :: VMS date (%e-%b-%Y)
# %V :: Week number of year according to ISO 8601 (01..53)
# %W :: Week number of the current year, starting with the first Monday
# as the first day of the first week (00..53)
# %w :: Day of the week (Sunday is 0, 0..6)
# %x :: Preferred representation for the date alone, no time
# %X :: Preferred representation for the time alone, no date
# %y :: Year without a century (00..99)
# %Y :: Year which may include century, if provided
# %z :: Time zone as hour offset from UTC (e.g. +0900)
# %Z :: Time zone name
# %% :: Literal "%" character
def strptime(date, format, now=self.now)
d = Date._strptime(date, format)
raise ArgumentError, "invalid strptime format - `#{format}'" unless d
if seconds = d[:seconds]
t = Time.at(seconds)
if zone = d[:zone]
force_zone!(t, zone)
end
else
year = d[:year]
year = yield(year) if year && block_given?
t = make_time(date, year, d[:mon], d[:mday], d[:hour], d[:min], d[:sec], d[:sec_fraction], d[:zone], now)
end
t
end
MonthValue = { # :nodoc:
'JAN' => 1, 'FEB' => 2, 'MAR' => 3, 'APR' => 4, 'MAY' => 5, 'JUN' => 6,
'JUL' => 7, 'AUG' => 8, 'SEP' => 9, 'OCT' =>10, 'NOV' =>11, 'DEC' =>12
}
#
# Parses +date+ as date-time defined by RFC 2822 and converts it to a Time
# object. The format is identical to the date format defined by RFC 822 and
# updated by RFC 1123.
#
# ArgumentError is raised if +date+ is not compliant with RFC 2822
# or if the Time class cannot represent specified date.
#
# See #rfc2822 for more information on this format.
#
# You must require 'time' to use this method.
#
def rfc2822(date)
if /\A\s*
(?:(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun)\s*,\s*)?
(\d{1,2})\s+
(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s+
(\d{2,})\s+
(\d{2})\s*
:\s*(\d{2})\s*
(?::\s*(\d{2}))?\s+
([+-]\d{4}|
UT|GMT|EST|EDT|CST|CDT|MST|MDT|PST|PDT|[A-IK-Z])/ix =~ date
# Since RFC 2822 permit comments, the regexp has no right anchor.
day = $1.to_i
mon = MonthValue[$2.upcase]
year = $3.to_i
short_year_p = $3.length <= 3
hour = $4.to_i
min = $5.to_i
sec = $6 ? $6.to_i : 0
zone = $7
if short_year_p
# following year completion is compliant with RFC 2822.
year = if year < 50
2000 + year
else
1900 + year
end
end
off = zone_offset(zone)
year, mon, day, hour, min, sec =
apply_offset(year, mon, day, hour, min, sec, off)
t = self.utc(year, mon, day, hour, min, sec)
force_zone!(t, zone, off)
t
else
raise ArgumentError.new("not RFC 2822 compliant date: #{date.inspect}")
end
end
alias rfc822 rfc2822
#
# Parses +date+ as an HTTP-date defined by RFC 2616 and converts it to a
# Time object.
#
# ArgumentError is raised if +date+ is not compliant with RFC 2616 or if
# the Time class cannot represent specified date.
#
# See #httpdate for more information on this format.
#
# You must require 'time' to use this method.
#
def httpdate(date)
if /\A\s*
(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun),\x20
(\d{2})\x20
(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\x20
(\d{4})\x20
(\d{2}):(\d{2}):(\d{2})\x20
GMT
\s*\z/ix =~ date
self.rfc2822(date).utc
elsif /\A\s*
(?:Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday),\x20
(\d\d)-(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)-(\d\d)\x20
(\d\d):(\d\d):(\d\d)\x20
GMT
\s*\z/ix =~ date
year = $3.to_i
if year < 50
year += 2000
else
year += 1900
end
self.utc(year, $2, $1.to_i, $4.to_i, $5.to_i, $6.to_i)
elsif /\A\s*
(?:Mon|Tue|Wed|Thu|Fri|Sat|Sun)\x20
(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\x20
(\d\d|\x20\d)\x20
(\d\d):(\d\d):(\d\d)\x20
(\d{4})
\s*\z/ix =~ date
self.utc($6.to_i, MonthValue[$1.upcase], $2.to_i,
$3.to_i, $4.to_i, $5.to_i)
else
raise ArgumentError.new("not RFC 2616 compliant date: #{date.inspect}")
end
end
#
# Parses +date+ as a dateTime defined by the XML Schema and converts it to
# a Time object. The format is a restricted version of the format defined
# by ISO 8601.
#
# ArgumentError is raised if +date+ is not compliant with the format or if
# the Time class cannot represent specified date.
#
# See #xmlschema for more information on this format.
#
# You must require 'time' to use this method.
#
def xmlschema(date)
if /\A\s*
(-?\d+)-(\d\d)-(\d\d)
T
(\d\d):(\d\d):(\d\d)
(\.\d+)?
(Z|[+-]\d\d:\d\d)?
\s*\z/ix =~ date
year = $1.to_i
mon = $2.to_i
day = $3.to_i
hour = $4.to_i
min = $5.to_i
sec = $6.to_i
usec = 0
if $7
usec = Rational($7) * 1000000
end
if $8
zone = $8
off = zone_offset(zone)
year, mon, day, hour, min, sec =
apply_offset(year, mon, day, hour, min, sec, off)
t = self.utc(year, mon, day, hour, min, sec, usec)
force_zone!(t, zone, off)
t
else
self.local(year, mon, day, hour, min, sec, usec)
end
else
raise ArgumentError.new("invalid date: #{date.inspect}")
end
end
alias iso8601 xmlschema
end # class << self
#
# Returns a string which represents the time as date-time defined by RFC 2822:
#
# day-of-week, DD month-name CCYY hh:mm:ss zone
#
# where zone is [+-]hhmm.
#
# If +self+ is a UTC time, -0000 is used as zone.
#
# You must require 'time' to use this method.
#
def rfc2822
sprintf('%s, %02d %s %0*d %02d:%02d:%02d ',
RFC2822_DAY_NAME[wday],
day, RFC2822_MONTH_NAME[mon-1], year < 0 ? 5 : 4, year,
hour, min, sec) +
if utc?
'-0000'
else
off = utc_offset
sign = off < 0 ? '-' : '+'
sprintf('%s%02d%02d', sign, *(off.abs / 60).divmod(60))
end
end
alias rfc822 rfc2822
RFC2822_DAY_NAME = [ # :nodoc:
'Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'
]
RFC2822_MONTH_NAME = [ # :nodoc:
'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'
]
#
# Returns a string which represents the time as RFC 1123 date of HTTP-date
# defined by RFC 2616:
#
# day-of-week, DD month-name CCYY hh:mm:ss GMT
#
# Note that the result is always UTC (GMT).
#
# You must require 'time' to use this method.
#
def httpdate
t = dup.utc
sprintf('%s, %02d %s %0*d %02d:%02d:%02d GMT',
RFC2822_DAY_NAME[t.wday],
t.day, RFC2822_MONTH_NAME[t.mon-1], t.year < 0 ? 5 : 4, t.year,
t.hour, t.min, t.sec)
end
#
# Returns a string which represents the time as a dateTime defined by XML
# Schema:
#
# CCYY-MM-DDThh:mm:ssTZD
# CCYY-MM-DDThh:mm:ss.sssTZD
#
# where TZD is Z or [+-]hh:mm.
#
# If self is a UTC time, Z is used as TZD. [+-]hh:mm is used otherwise.
#
# +fractional_digits+ specifies a number of digits to use for fractional
# seconds. Its default value is 0.
#
# You must require 'time' to use this method.
#
def xmlschema(fraction_digits=0)
fraction_digits = fraction_digits.to_i
s = strftime("%FT%T")
if fraction_digits > 0
s << strftime(".%#{fraction_digits}N")
end
s << (utc? ? 'Z' : strftime("%:z"))
end
alias iso8601 xmlschema
end