note
	description: "Absolute dates"
	legal: "See notice at end of class."
	status: "See notice at end of class."
	date: "$Date: 2017-03-29 12:26:46 +0000 (Wed, 29 Mar 2017) $"
	revision: "$Revision: 100065 $"
	access: date
	eis: "name=DATE / TIME to STRING Conversion", "src=$(ISE_DOC_UUID)/88972ba4-694b-8558-b0c8-87b1fc40afc4", "tag=EiffelTime"
	eis: "name=Obtaining a DATE from a DATE_TIME and vice versa", "src=$(ISE_DOC_UUID)/195849fc-1a9c-d734-2d2b-acae78133886#Obtaining_a_DATE_from_a_DATE_TIME_and_vice_versa", "tag=EiffelTime"

class interface
	DATE

create 
	make,
	make_month_day_year,
	make_day_month_year,
	make_now,
	make_now_utc,
	make_by_days,
	make_from_string_default,
	make_from_string_default_with_base,
	make_from_string,
	make_from_string_with_base,
	make_by_compact_date,
	make_by_ordered_compact_date

feature -- Initialization

	make (y, m, d: INTEGER_32)
			-- Set year, month and day to y, m, d respectively.
		require
			correct_date: is_correct_date (y, m, d)
		ensure
			year_set: year = y
			month_set: month = m
			day_set: day = d

	make_month_day_year (m, d, y: INTEGER_32)
			-- Set month, day and year to m, d and y respectively.
		require
			correct_date: is_correct_date (y, m, d)
		ensure
			year_set: year = y
			month_set: month = m
			day_set: day = d

	make_day_month_year (d, m, y: INTEGER_32)
			-- Set day, month and year to d, m and y respectively.
		require
			correct_date: is_correct_date (y, m, d)
		ensure
			year_set: year = y
			month_set: month = m
			day_set: day = d

	make_now
			-- Set the current object to today's date.

	make_now_utc
			-- Set the current object to today's date in utc format.

	make_by_days (n: INTEGER_32)
			-- Set the current date with the number of days n since Origin.
		ensure
			days_set: days = n

	make_from_string_default (s: STRING_8)
			-- Initialize from a "standard" string of form
			-- date_default_format_string.
			-- (For 2-digit year specifications, the current century is used as
			-- base century.)
		require
			s_exists: s /= Void
			date_valid: date_valid (s, date_default_format_string)

	make_from_string_default_with_base (s: STRING_8; base: INTEGER_32)
			-- Initialize from a "standard" string of form
			-- date_default_format_string with base century base.
		require
			s_exists: s /= Void
			base_valid: base > 0 and (base \\ 100 = 0)
			date_valid: date_valid_with_base (s, date_default_format_string, base)

	make_from_string (s: STRING_8; code: STRING_8)
			-- Initialize from a "standard" string of form
			-- code.
			-- (For 2-digit year specifications, the current century is used as
			-- base century.)
		require
			s_exists: s /= Void
			c_exists: code /= Void
			date_valid: date_valid (s, code)

	make_from_string_with_base (s: STRING_8; code: STRING_8; base: INTEGER_32)
			-- Initialize from a "standard" string of form
			-- code with base century base.
		require
			s_exists: s /= Void
			c_exists: code /= Void
			base_valid: base > 0 and (base \\ 100 = 0)
			date_valid: date_valid_with_base (s, code, base)

	make_by_ordered_compact_date (c_d: INTEGER_32)
			-- Initialize from a ordered_compact_date.
		require
			c_d_valid: ordered_compact_date_valid (c_d)
		ensure
			ordered_compact_date_set: ordered_compact_date = c_d
	
feature -- Access

	Origin: DATE
			-- Origin date
	
feature -- Comparison

	is_less alias "<" (other: like Current): BOOLEAN
			-- Is the current date before other?
	
feature -- Measurement

	duration: DATE_DURATION
			-- Definite duration elapsed since Origin
		ensure then
			definite_result: Result.definite
			duration_set: ((Current - Origin).duration).is_equal (Result)

	days: INTEGER_32
			-- Number of days elapsed since Origin
		ensure
			same_duration: Result = duration.day
	
feature -- Status report

	leap_year: BOOLEAN
			-- Is the current year a leap year?

	days_at_month: INTEGER_32
			-- Number of days from the beginning of the year
			-- until the beginning of the current month
		ensure
			positive_result: Result >= 0

	year_day: INTEGER_32
			-- Number of days from the beginning of the year
		ensure
			result_large_enough: Result >= 1
			result_small_enough: Result <= days_in_year

	week_of_year: INTEGER_32
			-- Number of weeks from the beginning of the year
			-- The first week of the year begins on the first sunday of the year
			-- The week number before the first sunday of the year is 0
		ensure
			positive_result: Result >= 0
			result_small_enough: Result < Max_weeks_in_year

	days_in_year: INTEGER_32
			-- Number of days in the current year
		ensure
			valid_result: (leap_year implies Result = Days_in_leap_year) and then (not leap_year implies Result = Days_in_non_leap_year)

	day_of_the_week: INTEGER_32
			-- Number of day from the beginning of the week
			-- sunday is 1, etc.., saturday is 7
		ensure
			day_of_the_week_range: Result > 0 and then Result < 8

	day_of_january_1st: INTEGER_32
			-- Day of the week of january 1st of the current year
		ensure
			day_of_the_week_definition: Result > 0 and then Result < 8

	days_from (y: INTEGER_32): INTEGER_32
			-- Days between the current year and year y
	
feature -- Conversion

	to_date_time: DATE_TIME
			-- Date-time version, with a zero time component
	
feature -- Basic operations

	plus alias "+" (d: DATE_DURATION): DATE
			-- Sum to current date the duration d
			-- if duration not define, add years and then months and then days.
		require
			d_not_void: d /= Void
		ensure
			result_exists: Result /= Void
			definite_set: d.definite implies (Result - Current).duration.is_equal (d)

	add (d: DATE_DURATION)
			-- Adds d to the current date.
			-- if d is not definite, add years and months and then days.
		require
			d_not_void: d /= Void

	relative_duration (other: like Current): DATE_DURATION
			-- Duration from other to the current date
		ensure then
			exact_duration: (other + Result).is_equal (Current)
			canonical_duration: Result.canonical (other)
			origin_date_set: equal (Result.origin_date, other)

	day_forth
			-- Move to next day.
			-- days is from the origin, day is current.
		ensure
			days_set: days = old days + 1

	day_back
			-- Move to previous day.
		ensure
			days_set: days = old days - 1

	day_add (d: INTEGER_32)
			-- Add d days to the current date.
		ensure
			days_set: days = old days + d

	month_forth
			-- Move to next month.
			-- Can move days backward if next month has less days than the
			-- current month.

	month_back
			-- Move to previous month.
			-- Can move days backward if previous month has less days than the
			-- current month.

	month_add (m: INTEGER_32)
			-- Add m months to the current date.
			-- Can move days backward.

	year_forth
			-- Move to next year.
			-- May cut the 29th february.
		ensure
			year_increased: year = old year + 1

	year_back
			-- Move to previous year.
			-- May cut the 29th february.
		ensure
			year_decreased: year = old year - 1

	year_add (y: INTEGER_32)
			-- Add y years to the current date.
			-- May cut the 29th february.
		ensure
			year_set: year = old year + y

	year_month_add (y, m: INTEGER_32)
			-- Add y years and m months to the current date.
			-- Check the number of days after.
	
feature -- Output

	debug_output: STRING_8
			-- Printable representation of Current with "standard"
			-- Form: date_default_format_string
			-- Was declared in DATE as synonym of out.

	out: STRING_8
			-- Printable representation of Current with "standard"
			-- Form: date_default_format_string
			-- Was declared in DATE as synonym of debug_output.

	formatted_out (s: STRING_8): STRING_8
			-- Printable representation of Current with "standard"
			-- Form: s
		require
			s_exists: s /= Void
	
invariant
	day_large_enough: day >= 1
	day_small_enough: day <= days_in_month
	month_large_enough: month >= 1
	month_small_enough: month <= Months_in_year
	year_small_enough: year <= 65535
	year_non_negative: year >= 0

note
	copyright: "Copyright (c) 1984-2017, Eiffel Software and others"
	license: "Eiffel Forum License v2 (see http://www.eiffel.com/licensing/forum.txt)"
	source: "[
		Eiffel Software
		5949 Hollister Ave., Goleta, CA 93117 USA
		Telephone 805-685-1006, Fax 805-685-6869
		Website http://www.eiffel.com
		Customer support http://support.eiffel.com
	]"

end -- class DATE

Generated by ISE EiffelStudio