Data.Time.Clock.POSIX

POSIX time, if you need to deal with timestamps and the like. Most people won't need this module.

You can use POSIXTime to obtain integer/word timestamps. For example:

import Data.Time
import Data.Time.Clock.POSIX
import Data.Int

nanosSinceEpoch :: UTCTime -> Int64
nanosSinceEpoch =
    floor . (1e9 *) . nominalDiffTimeToSeconds . utcTimeToPOSIXSeconds

main :: IO ()
main = do
    u <- getCurrentTime
    print $ nanosSinceEpoch u

Documentation

posixDayLength :: NominalDiffTime

86400 nominal seconds in every day

type POSIXTime = NominalDiffTime

POSIX time is the nominal time since 1970-01-01 00:00 UTC

To convert from a CTime or System.Posix.EpochTime, use realToFrac.

posixSecondsToUTCTime :: POSIXTime -> UTCTime

utcTimeToPOSIXSeconds :: UTCTime -> POSIXTime

getPOSIXTime :: IO POSIXTime

Get the current POSIX time from the system clock.

getCurrentTime :: IO UTCTime

Get the current UTCTime from the system clock.

systemToPOSIXTime :: SystemTime -> POSIXTime