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GHC 9.10.3 · lts/ghc-9.10.x · c74966e · 2026-09-27

Moduletime-1.12.2Haskell2010

Data.Time.Calendar.WeekDate

Week-based calendars

  • 4 types
  • 8 values
  • Packagetime-1.12.2
  • Exports13
  • LanguageHaskell2010
  • LicenceBSD-2-Clause
  • SourceWeekDate.hs
typetype Year = Integer
#

Year of Common Era (when positive).

typetype WeekOfYear = Int
#

Week of year, by various reckonings, generally in range 0-53 depending on reckoning.

datadata DayOfWeek
#
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Instances9Enum, Eq, Data, Ord, Read, Show, …
  • Enum DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week

    "Circular", so for example [Tuesday ..] gives an endless sequence. Also: fromEnum gives [1 .. 7] for [Monday .. Sunday], and toEnum performs mod 7 to give a cycle of days.

  • Eq DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week
  • Data DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week
  • Ord DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week
  • Read DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week
  • Show DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week
  • Ix DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week
  • NFData DayOfWeekDefined in time-1.12.2 · Data.Time.Calendar.Week
  • FormatTime DayOfWeekDefined in time-1.12.2 · Data.Time.Format.Format.Instances · orphan

ISO 8601 Week Date format

5 declarations
valuetoWeekDate :: Day -> (Year, WeekOfYear, Int)
#

Convert to ISO 8601 Week Date format. First element of result is year, second week number (1-53), third day of week (1 for Monday to 7 for Sunday). Note that "Week" years are not quite the same as Gregorian years, as the first day of the year is always a Monday. The first week of a year is the first week to contain at least four days in the corresponding Gregorian year.

valuefromWeekDate :: Year -> WeekOfYear -> Int -> Day
#

Convert from ISO 8601 Week Date format. First argument is year, second week number (1-52 or 53), third day of week (1 for Monday to 7 for Sunday). Invalid week and day values will be clipped to the correct range.

patternpattern YearWeekDay :: Year -> WeekOfYear -> DayOfWeek -> Day
#

Bidirectional abstract constructor for ISO 8601 Week Date format. Invalid week values will be clipped to the correct range.

valuefromWeekDateValid :: Year -> WeekOfYear -> Int -> Maybe Day
#

Convert from ISO 8601 Week Date format. First argument is year, second week number (1-52 or 53), third day of week (1 for Monday to 7 for Sunday). Invalid week and day values will return Nothing.