diff options
Diffstat (limited to 'lib/date.rb')
| -rw-r--r-- | lib/date.rb | 114 |
1 files changed, 53 insertions, 61 deletions
diff --git a/lib/date.rb b/lib/date.rb index 21e35a6660..0747da1295 100644 --- a/lib/date.rb +++ b/lib/date.rb @@ -1,20 +1,20 @@ -# +# # date.rb - date and time library # -# Author: Tadayoshi Funaba 1998-2002 +# Author: Tadayoshi Funaba 1998-2004 # # Documentation: William Webber <[email protected]> # #-- -# $Id: date.rb,v 2.8 2002-06-08 00:39:51+09 tadf Exp $ +# $Id: date.rb,v 2.11 2004-01-19 04:56:12+09 tadf Exp $ #++ # # == Overview # # This file provides two classes for working with # dates and times. -# -# The first class, Date, represents dates. +# +# The first class, Date, represents dates. # It works with years, months, weeks, and days. # See the Date class documentation for more details. # @@ -28,11 +28,11 @@ # In common usage, the date is reckoned in years since or # before the Common Era (CE/BCE, also known as AD/BC), then # as a month and day-of-the-month within the current year. -# This is known as the *Civil* *Date*, and abbrevated +# This is known as the *Civil* *Date*, and abbrevated # as +civil+ in the Date class. # -# Instead of year, month-of-the-year, and day-of-the-month, -# the date can also be reckoned in terms of year and +# Instead of year, month-of-the-year, and day-of-the-month, +# the date can also be reckoned in terms of year and # day-of-the-year. This is known as the *Ordinal* *Date*, # and is abbreviated as +ordinal+ in the Date class. (Note # that referring to this as the Julian date is incorrect.) @@ -58,7 +58,7 @@ # Date class as the *Astronomical* *Julian* *Day* *Number*, and # abbreviated as +ajd+. In the Date class, the Astronomical # Julian Day Number includes fractional days. -# +# # Another absolute day count is the *Modified* *Julian* *Day* # *Number*, which takes November 17, 1858 as its initial day. # This is abbreviated as +mjd+ in the Date class. There @@ -80,7 +80,7 @@ # The standard civil year is 365 days long. However, the # solar year is fractionally longer than this. To account # for this, a *leap* *year* is occasionally inserted. This -# is a year with 366 days, the extra day falling on February 29. +# is a year with 366 days, the extra day falling on February 29. # In the early days of the civil calendar, every fourth # year without exception was a leap year. This way of # reckoning leap years is the *Julian* *Calendar*. @@ -94,7 +94,7 @@ # # The Gregorian Calendar was introduced at different times # in different regions. The day on which it was introduced -# for a particular region is the *Day* *of* *Calendar* +# for a particular region is the *Day* *of* *Calendar* # *Reform* for that region. This is abbreviated as +sg+ # (for Start of Gregorian calendar) in the Date class. # @@ -103,24 +103,24 @@ # the Day of Calendar Reform for Italy and most Catholic # countries. The second is September 14, 1752, which was # the Day of Calendar Reform for England and its colonies -# (including what is now the United States). These two +# (including what is now the United States). These two # dates are available as the constants Date::ITALY and # Date::ENGLAND, respectively. (By comparison, Germany and # Holland, less Catholic than Italy but less stubborn than # England, changed over in 1698; Sweden in 1753; Russia not # till 1918, after the Revolution; and Greece in 1923. Many # Orthodox churches still use the Julian Calendar. A complete -# list of Days of Calendar Reform can be found at +# list of Days of Calendar Reform can be found at # http://www.polysyllabic.com/GregConv.html.) # # Switching from the Julian to the Gregorian calendar # involved skipping a number of days to make up for the # accumulated lag, and the later the switch was (or is) # done, the more days need to be skipped. So in 1582 in Italy, -# 4th October was followed by 15th October, skipping 10 days; in 1752 +# 4th October was followed by 15th October, skipping 10 days; in 1752 # in England, 2nd September was followed by 14th September, skipping -# 11 days; and if I decided to switch from Julian to Gregorian -# Calendar this midnight, I would go from 27th July 2003 (Julian) +# 11 days; and if I decided to switch from Julian to Gregorian +# Calendar this midnight, I would go from 27th July 2003 (Julian) # today to 10th August 2003 (Gregorian) tomorrow, skipping # 13 days. The Date class is aware of this gap, and a supposed # date that would fall in the middle of it is regarded as invalid. @@ -148,13 +148,13 @@ # of time zones. Time zones are represented as an offset # from UTC, as a fraction of a day. This offset is the # how much local time is later (or earlier) than UTC. -# UTC offset 0 is centred on England (also known as GMT). +# UTC offset 0 is centred on England (also known as GMT). # As you travel east, the offset increases until you # reach the dateline in the middle of the Pacific Ocean; # as you travel west, the offset decreases. This offset # is abbreviated as +of+ in the Date class. # -# This simple representation of time zones does not take +# This simple representation of time zones does not take # into account the common practice of Daylight Savings # Time or Summer Time. # @@ -201,7 +201,7 @@ require 'date/format' # See the documentation to the file date.rb for an overview. # # Internally, the date is represented as an Astronomical -# Julian Day Number, +ajd+. The Day of Calendar Reform, +sg+, is +# Julian Day Number, +ajd+. The Day of Calendar Reform, +sg+, is # also stored, for conversions to other date formats. (There # is also an +of+ field for a time zone offset, but this # is only for the use of the DateTime subclass.) @@ -217,7 +217,7 @@ require 'date/format' # Date objects are immutable once created. # # Once a Date has been created, date values -# can be retrieved for the different date formats supported +# can be retrieved for the different date formats supported # using instance methods. For instance, #mon() gives the # Civil month, #cwday() gives the Commercial day of the week, # and #yday() gives the Ordinal day of the year. Date values @@ -237,7 +237,7 @@ class Date MONTHNAMES = [nil] + %w(January February March April May June July August September October November December) - # Full names of days of the week, in English. Days of the week + # Full names of days of the week, in English. Days of the week # count from 0 to 6 (except in the commercial week); a day's numerical # represenation indexed into this array gives the name of that day. DAYNAMES = %w(Sunday Monday Tuesday Wednesday Thursday Friday Saturday) @@ -312,7 +312,7 @@ class Date # the Julian Day Number. +sg+ specifies the Day of # Calendar Reform. # - # Returns the corresponding [year, month, day_of_month] + # Returns the corresponding [year, month, day_of_month] # as a three-element array. def self.jd_to_civil(jd, sg=GREGORIAN) if os?(jd, sg) @@ -351,7 +351,7 @@ class Date # +jd+ is the Julian Day Number to convert. # +sg+ specifies the Day of Calendar Reform. # - # Returns the corresponding Ordinal Date as + # Returns the corresponding Ordinal Date as # [year, day_of_year] def self.jd_to_ordinal(jd, sg=GREGORIAN) y = jd_to_civil(jd, sg)[0] @@ -378,7 +378,7 @@ class Date # Convert a Commercial Date to a Julian Day Number. # - # +y+, +w+, and +d+ are the (commercial) year, week of the year, + # +y+, +w+, and +d+ are the (commercial) year, week of the year, # and day of the week of the Commercial Date to convert. # +sg+ specifies the Day of Calendar Reform. def self.commercial_to_jd(y, w, d, ns=GREGORIAN) @@ -405,7 +405,7 @@ class Date # Convert an Astronomical Julian Day Number to a (civil) Julian # Day Number. # - # +ajd+ is the Astronomical Julian Day Number to convert. + # +ajd+ is the Astronomical Julian Day Number to convert. # +of+ is the offset from UTC as a fraction of a day (defaults to 0). # # Returns the (civil) Julian Day Number as [day_number, @@ -416,10 +416,10 @@ class Date # Day Number. # # +jd+ is the Julian Day Number to convert, and +fr+ is a - # fractional day. + # fractional day. # +of+ is the offset from UTC as a fraction of a day (defaults to 0). # - # Returns the Astronomical Julian Day Number as a single + # Returns the Astronomical Julian Day Number as a single # numeric value. def self.jd_to_ajd(jd, fr, of=0) jd + fr - of - 1.to_r/2 end @@ -438,7 +438,7 @@ class Date h.to_r/24 + min.to_r/1440 + s.to_r/86400 end - # Convert an Astronomical Modified Julian Day Number to an + # Convert an Astronomical Modified Julian Day Number to an # Astronomical Julian Day Number. def self.amjd_to_ajd(amjd) amjd + 4800001.to_r/2 end @@ -450,7 +450,7 @@ class Date # Day Number. def self.mjd_to_jd(mjd) mjd + 2400001 end - # Convert a Julian Day Number to a Modified Julian Day + # Convert a Julian Day Number to a Modified Julian Day # Number. def self.jd_to_mjd(jd) jd - 2400001 end @@ -490,7 +490,7 @@ class Date # Create a new Date object from a Julian Day Number. # # +jd+ is the Julian Day Number; if not specified, it defaults to - # 0. + # 0. # +sg+ specifies the Day of Calendar Reform. def self.jd(jd=0, sg=ITALY) jd = valid_jd?(jd, sg) @@ -504,8 +504,8 @@ class Date # +d+ can be a negative number, in which case it counts backwards # from the end of the year (-1 being the last day of the year). # No year wraparound is performed, however, so valid values of - # +d+ are -365 .. -1, 1 .. 365 on a non-leap-year, - # -366 .. -1, 1 .. 366 on a leap year. + # +d+ are -365 .. -1, 1 .. 365 on a non-leap-year, + # -366 .. -1, 1 .. 366 on a leap year. # A date falling in the period skipped in the Day of Calendar Reform # adjustment is not valid. # @@ -541,15 +541,15 @@ class Date new0(jd_to_ajd(jd, 0, 0), 0, sg) end - # Do year +y+, month +m+, and day-of-month +d+ make a - # valid Civil Date? Returns the corresponding Julian + # Do year +y+, month +m+, and day-of-month +d+ make a + # valid Civil Date? Returns the corresponding Julian # Day Number if they do, nil if they don't. # # +m+ and +d+ can be negative, in which case they count # backwards from the end of the year and the end of the # month respectively. No wraparound is performed, however, # and invalid values cause an ArgumentError to be raised. - # A date falling in the period skipped in the Day of Calendar + # A date falling in the period skipped in the Day of Calendar # Reform adjustment is not valid. # # +sg+ specifies the Day of Calendar Reform. @@ -580,7 +580,7 @@ class Date # backwards from the end of the year and the end of the # month respectively. No wraparound is performed, however, # and invalid values cause an ArgumentError to be raised. - # can be negative + # can be negative # # +y+ defaults to -4712, +m+ to 1, and +d+ to 1; this is # Julian Day Number day 0. @@ -605,7 +605,7 @@ class Date # backwards from the end of the year and the end of the # week respectively. No wraparound is performed, however, # and invalid values cause an ArgumentError to be raised. - # A date falling in the period skipped in the Day of Calendar + # A date falling in the period skipped in the Day of Calendar # Reform adjustment is not valid. # # +sg+ specifies the Day of Calendar Reform. @@ -659,7 +659,7 @@ class Date # according to a specified format. # # +str+ is a String holding a date representation. - # +fmt+ is the format that the date is in. See + # +fmt+ is the format that the date is in. See # date/format.rb for details on supported formats. # # The default +str+ is '-4712-01-01', and the default @@ -678,7 +678,7 @@ class Date # Create a new Date object by parsing from a String, # without specifying the format. # - # +str+ is a String holding a date representation. + # +str+ is a String holding a date representation. # +comp+ specifies whether to interpret 2-digit years # as 19XX (>= 69) or 20XX (< 69); the default is not to. # The method will attempt to parse a date from the String @@ -723,7 +723,7 @@ class Date # *NOTE* this is the documentation for the method new0(). If # you are reading this as the documentation for new(), that is - # because rdoc doesn't fully support the aliasing of the + # because rdoc doesn't fully support the aliasing of the # initialize() method. # new() is in # fact an alias for #civil(): read the documentation for that @@ -731,9 +731,9 @@ class Date # # Create a new Date object. # - # +ajd+ is the Astronomical Julian Day Number. + # +ajd+ is the Astronomical Julian Day Number. # +of+ is the offset from UTC as a fraction of a day. - # Both default to 0. + # Both default to 0. # # +sg+ specifies the Day of Calendar Reform to use for this # Date object. @@ -817,13 +817,7 @@ class Date private :hour, :min, :sec, :sec_fraction - def zone - ['Z', - format('%+.2d%02d', - (@of / (1.to_r/24)).to_i, - (@of.abs % (1.to_r/24) / (1.to_r/1440)).to_i) - ][@of<=>0] - end + def zone() strftime('%Z') end private :zone @@ -921,7 +915,7 @@ class Date # Compare this date with another date. # - # +other+ can also be a Numeric value, in which case it is + # +other+ can also be a Numeric value, in which case it is # interpreted as an Astronomical Julian Day Number. # # Comparison is by Astronomical Julian Day Number, including @@ -975,7 +969,7 @@ class Date def << (n) self >> -n end # Step the current date forward +step+ days at a - # time (or backward, if +step+ is negative) until + # time (or backward, if +step+ is negative) until # we reach +limit+ (inclusive), yielding the resultant # date at each step. def step(limit, step) # :yield: date @@ -991,13 +985,13 @@ class Date # Step forward one day at a time until we reach +max+ # (inclusive), yielding each date as we go. def upto(max, &block) # :yield: date - step(max, +1, &block) - end + step(max, +1, &block) + end # Step backward one day at a time until we reach +min+ # (inclusive), yielding each date as we go. def downto(min, &block) # :yield: date - step(min, -1, &block) + step(min, -1, &block) end # Return a new Date one day after this one. @@ -1057,7 +1051,7 @@ end # # Get the hour-of-the-day of the time. This is given # using the 24-hour clock, counting from midnight. The first -# hour after midnight is hour 0; the last hour of the day is +# hour after midnight is hour 0; the last hour of the day is # hour 23. # # === min() @@ -1165,7 +1159,7 @@ class DateTime < Date # +of+ is the offset from UTC as a fraction of a day (defaults to 0). # +sg+ specifies the Day of Calendar Reform. # - # +y+ defaults to -4712, +m+ to 1, and +d+ to 1; this is Julian Day + # +y+ defaults to -4712, +m+ to 1, and +d+ to 1; this is Julian Day # Number day 0. The time values default to 0. def self.civil(y=-4712, m=1, d=1, h=0, min=0, s=0, of=0, sg=ITALY) unless (jd = valid_civil?(y, m, d, sg)) and @@ -1221,7 +1215,7 @@ class DateTime < Date # according to a specified format. # # +str+ is a String holding a date-time representation. - # +fmt+ is the format that the date-time is in. See + # +fmt+ is the format that the date-time is in. See # date/format.rb for details on supported formats. # # The default +str+ is '-4712-01-01T00:00:00Z', and the default @@ -1239,7 +1233,7 @@ class DateTime < Date # Create a new DateTime object by parsing from a String, # without specifying the format. # - # +str+ is a String holding a date-time representation. + # +str+ is a String holding a date-time representation. # +comp+ specifies whether to interpret 2-digit years # as 19XX (>= 69) or 20XX (< 69); the default is not to. # The method will attempt to parse a date-time from the String @@ -1266,9 +1260,7 @@ class DateTime < Date a = i.to_a[0..5].reverse jd = civil_to_jd(*(a[0,3] << sg)) fr = time_to_day_fraction(*(a[3,3])) + i.usec.to_r/86400000000 - d = Time.gm(*i.to_a).to_i - i.to_i - d += d / d.abs if d.nonzero? - of = (d / 60).to_r/1440 + of = i.utc_offset.to_r/86400 new0(jd_to_ajd(jd, fr, of), of, sg) end |