{-# OPTIONS -Wall -Werror -fno-warn-orphans #-} -- #hide module Data.Time.LocalTime.LocalTime ( -- * Local Time LocalTime(..), -- converting UTC and UT1 times to LocalTime utcToLocalTime,localTimeToUTC,ut1ToLocalTime,localTimeToUT1, ZonedTime(..),utcToZonedTime,zonedTimeToUTC,getZonedTime,utcToLocalZonedTime ) where import Data.Time.LocalTime.TimeOfDay import Data.Time.LocalTime.TimeZone import Data.Time.Calendar import Data.Time.Clock -- | A simple day and time aggregate, where the day is of the specified parameter, -- and the time is a TimeOfDay. -- Conversion of this (as local civil time) to UTC depends on the time zone. -- Conversion of this (as local mean time) to UT1 depends on the longitude. data LocalTime = LocalTime { localDay :: Day, localTimeOfDay :: TimeOfDay } deriving (Eq,Ord) instance Show LocalTime where show (LocalTime d t) = (showGregorian d) ++ " " ++ (show t) -- | show a UTC time in a given time zone as a LocalTime utcToLocalTime :: TimeZone -> UTCTime -> LocalTime utcToLocalTime tz (UTCTime day dt) = LocalTime (addDays i day) tod where (i,tod) = utcToLocalTimeOfDay tz (timeToTimeOfDay dt) -- | find out what UTC time a given LocalTime in a given time zone is localTimeToUTC :: TimeZone -> LocalTime -> UTCTime localTimeToUTC tz (LocalTime day tod) = UTCTime (addDays i day) (timeOfDayToTime todUTC) where (i,todUTC) = localToUTCTimeOfDay tz tod -- | 1st arg is observation meridian in degrees, positive is East ut1ToLocalTime :: Rational -> UniversalTime -> LocalTime ut1ToLocalTime long (ModJulianDate date) = LocalTime (ModifiedJulianDay localMJD) (dayFractionToTimeOfDay localToDOffset) where localTime = date + long / 360 :: Rational localMJD = floor localTime localToDOffset = localTime - (fromIntegral localMJD) -- | 1st arg is observation meridian in degrees, positive is East localTimeToUT1 :: Rational -> LocalTime -> UniversalTime localTimeToUT1 long (LocalTime (ModifiedJulianDay localMJD) tod) = ModJulianDate ((fromIntegral localMJD) + (timeOfDayToDayFraction tod) - (long / 360)) -- | A local time together with a TimeZone. data ZonedTime = ZonedTime { zonedTimeToLocalTime :: LocalTime, zonedTimeZone :: TimeZone } utcToZonedTime :: TimeZone -> UTCTime -> ZonedTime utcToZonedTime zone time = ZonedTime (utcToLocalTime zone time) zone zonedTimeToUTC :: ZonedTime -> UTCTime zonedTimeToUTC (ZonedTime t zone) = localTimeToUTC zone t instance Show ZonedTime where show (ZonedTime t zone) = show t ++ " " ++ show zone instance Show UTCTime where show t = show (utcToZonedTime utc t) getZonedTime :: IO ZonedTime getZonedTime = do t <- getCurrentTime zone <- getTimeZone t return (utcToZonedTime zone t) -- | utcToLocalZonedTime :: UTCTime -> IO ZonedTime utcToLocalZonedTime t = do zone <- getTimeZone t return (utcToZonedTime zone t)