-- #hide module Data.Time.LocalTime.TimeOfDay ( -- * Time of day TimeOfDay(..),midnight,midday, utcToLocalTimeOfDay,localToUTCTimeOfDay, timeToTimeOfDay,timeOfDayToTime, dayFractionToTimeOfDay,timeOfDayToDayFraction ) where import Data.Time.LocalTime.TimeZone import Data.Time.Calendar.Private import Data.Time.Clock import Data.Fixed -- | Time of day as represented in hour, minute and second (with picoseconds), typically used to express local time of day. data TimeOfDay = TimeOfDay { -- | range 0 - 23 todHour :: Int, -- | range 0 - 59 todMin :: Int, -- | Note that 0 <= todSec < 61, accomodating leap seconds. -- Any local minute may have a leap second, since leap seconds happen in all zones simultaneously todSec :: Pico } deriving (Eq,Ord) -- | Hour zero midnight :: TimeOfDay midnight = TimeOfDay 0 0 0 -- | Hour twelve midday :: TimeOfDay midday = TimeOfDay 12 0 0 instance Show TimeOfDay where show (TimeOfDay h m s) = (show2 h) ++ ":" ++ (show2 m) ++ ":" ++ (show2Fixed s) -- | Convert a ToD in UTC to a ToD in some timezone, together with a day adjustment. utcToLocalTimeOfDay :: TimeZone -> TimeOfDay -> (Integer,TimeOfDay) utcToLocalTimeOfDay zone (TimeOfDay h m s) = (fromIntegral (div h' 24),TimeOfDay (mod h' 24) (mod m' 60) s) where m' = m + timeZoneMinutes zone h' = h + (div m' 60) -- | Convert a ToD in some timezone to a ToD in UTC, together with a day adjustment. localToUTCTimeOfDay :: TimeZone -> TimeOfDay -> (Integer,TimeOfDay) localToUTCTimeOfDay zone = utcToLocalTimeOfDay (minutesToTimeZone (negate (timeZoneMinutes zone))) posixDayLength :: DiffTime posixDayLength = fromInteger 86400 -- | Get a TimeOfDay given a time since midnight. -- Time more than 24h will be converted to leap-seconds. timeToTimeOfDay :: DiffTime -> TimeOfDay timeToTimeOfDay dt | dt >= posixDayLength = TimeOfDay 23 59 (60 + (realToFrac (dt - posixDayLength))) timeToTimeOfDay dt = TimeOfDay (fromInteger h) (fromInteger m) s where s' = realToFrac dt s = mod' s' 60 m' = div' s' 60 m = mod' m' 60 h = div' m' 60 -- | Find out how much time since midnight a given TimeOfDay is. timeOfDayToTime :: TimeOfDay -> DiffTime timeOfDayToTime (TimeOfDay h m s) = ((fromIntegral h) * 60 + (fromIntegral m)) * 60 + (realToFrac s) -- | Get a TimeOfDay given the fraction of a day since midnight. dayFractionToTimeOfDay :: Rational -> TimeOfDay dayFractionToTimeOfDay df = timeToTimeOfDay (realToFrac (df * 86400)) -- | Get the fraction of a day since midnight given a TimeOfDay. timeOfDayToDayFraction :: TimeOfDay -> Rational timeOfDayToDayFraction tod = realToFrac (timeOfDayToTime tod / posixDayLength)