Дата и время

module Time (
ClockTime, 
Month(January,February,March,April,May,June,
      July,August,September,October,November,December),
Day(Sunday,Monday,Tuesday,Wednesday,Thursday,Friday,Saturday),
CalendarTime(CalendarTime, ctYear, ctMonth, ctDay, ctHour, ctMin,
     ctSec, ctPicosec, ctWDay, ctYDay, 
                     ctTZName, ctTZ, ctIsDST),
TimeDiff(TimeDiff, tdYear, tdMonth, tdDay, tdHour,
 tdMin, tdSec, tdPicosec),
getClockTime, addToClockTime, diffClockTimes,
        toCalendarTime, toUTCTime, toClockTime,
        calendarTimeToString, formatCalendarTime ) where

import Ix(Ix)

data ClockTime = ... - Зависит от реализации
instance Ord  ClockTime where ...
instance Eq   ClockTime where ...

data Month =  January   | February | March    | April
           |  May       | June     | July     | August
           |  September | October  | November | December
           deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)

data Day   =  Sunday | Monday  | Tuesday  | Wednesday | Thursday 
           |  Friday | Saturday
           deriving (Eq, Ord, Enum, Bounded, Ix, Read, Show)

data CalendarTime = CalendarTime {
ctYear   :: Int,
        ctMonth  :: Month,
        ctDay, ctHour, ctMin, ctSec  :: Int,
ctPicosec :: Integer,
ctWDay    :: Day,
ctYDay       :: Int,
ctTZName   :: String,
ctTZ          :: Int,
ctIsDST :: Bool
} deriving (Eq, Ord, Read, Show)

data TimeDiff = TimeDiff {
tdYear, tdMonth, tdDay, tdHour, tdMin, tdSec :: Int,
tdPicosec      :: Integer
} deriving (Eq, Ord, Read, Show)
- Функции со временем
getClockTime         :: IO ClockTime
     
addToClockTime       :: TimeDiff  -> ClockTime -> ClockTime
diffClockTimes       :: ClockTime -> ClockTime -> TimeDiff
     
toCalendarTime       :: ClockTime    -> IO CalendarTime
toUTCTime            :: ClockTime    -> CalendarTime
toClockTime          :: CalendarTime -> ClockTime
calendarTimeToString :: CalendarTime -> String
formatCalendarTime   :: TimeLocale -> String -> CalendarTime -> String