Data.UnixTime

Data structure

data UnixTime

Data structure for Unix time.

Please note that this uses GHC-derived Eq and Ord instances. Notably

>>> UnixTime 1 0 > UnixTime 0 999999999
True

You should instead use UnixDiffTime along with its helpers such as microSecondsToUnixDiffTime which will ensure that such unusual values are never created.

Constructors

UnixTime

Fields

• utSeconds :: !CTime

  Seconds from 1st Jan 1970

• utMicroSeconds :: !Int32

  Micro seconds (i.e. 10^(-6))

Instances

Eq UnixTime

Methods

(==) :: UnixTime -> UnixTime -> Bool

(/=) :: UnixTime -> UnixTime -> Bool

Ord UnixTime

Methods

compare :: UnixTime -> UnixTime -> Ordering

(<) :: UnixTime -> UnixTime -> Bool

(<=) :: UnixTime -> UnixTime -> Bool

(>) :: UnixTime -> UnixTime -> Bool

(>=) :: UnixTime -> UnixTime -> Bool

max :: UnixTime -> UnixTime -> UnixTime

min :: UnixTime -> UnixTime -> UnixTime

Show UnixTime

Methods

showsPrec :: Int -> UnixTime -> ShowS

show :: UnixTime -> String

showList :: [UnixTime] -> ShowS

Storable UnixTime

Methods

sizeOf :: UnixTime -> Int

alignment :: UnixTime -> Int

peekElemOff :: Ptr UnixTime -> Int -> IO UnixTime

pokeElemOff :: Ptr UnixTime -> Int -> UnixTime -> IO ()

peekByteOff :: Ptr b -> Int -> IO UnixTime

pokeByteOff :: Ptr b -> Int -> UnixTime -> IO ()

peek :: Ptr UnixTime -> IO UnixTime

poke :: Ptr UnixTime -> UnixTime -> IO ()

Binary UnixTime

Methods

put :: UnixTime -> Put

get :: Get UnixTime

putList :: [UnixTime] -> Put

Getting time

getUnixTime :: IO UnixTime

Getting UnixTime from OS.

Parsing and formatting time

parseUnixTime :: Format -> ByteString -> UnixTime

Parsing ByteString to UnixTime interpreting as localtime. This is a wrapper for strptime_l(). Many implementations of strptime_l() do not support %Z and some implementations of strptime_l() do not support %z, either. utMicroSeconds is always set to 0.

parseUnixTimeGMT :: Format -> ByteString -> UnixTime

Parsing ByteString to UnixTime interpreting as GMT. This is a wrapper for strptime_l(). utMicroSeconds is always set to 0.

>>> parseUnixTimeGMT webDateFormat "Thu, 01 Jan 1970 00:00:00 GMT"
UnixTime {utSeconds = 0, utMicroSeconds = 0}

formatUnixTime :: Format -> UnixTime -> IO ByteString

Formatting UnixTime to ByteString in local time. This is a wrapper for strftime_l(). utMicroSeconds is ignored. The result depends on the TZ environment variable.

formatUnixTimeGMT :: Format -> UnixTime -> ByteString

Formatting UnixTime to ByteString in GMT. This is a wrapper for strftime_l(). utMicroSeconds is ignored.

>>> formatUnixTimeGMT webDateFormat $ UnixTime 0 0
"Thu, 01 Jan 1970 00:00:00 GMT"
>>> let ut = UnixTime 100 200
>>> let str = formatUnixTimeGMT "%s" ut
>>> let ut' = parseUnixTimeGMT "%s" str
>>> ((==) `on` utSeconds) ut ut'
True
>>> ((==) `on` utMicroSeconds) ut ut'
False

Format

type Format = ByteString

Format of the strptime()/strftime() style.

webDateFormat :: Format

Format for web (RFC 2616). The value is "%a, %d %b %Y %H:%M:%S GMT". This should be used with formatUnixTimeGMT and parseUnixTimeGMT.

mailDateFormat :: Format

Format for e-mail (RFC 5322). The value is "%a, %d %b %Y %H:%M:%S %z". This should be used with formatUnixTime and parseUnixTime.

Difference time

data UnixDiffTime

Data structure for UnixTime diff.

It is up to the user to ensure that udtMicroSeconds < 1000000. Helpers such as microSecondsToUnixDiffTime can help you to create valid values. For example, it's a mistake to use addUnixDiffTime with a value UnixDiffTime 0 9999999 as it will produce an incorrect value back. You should instead use functions such as microSecondsToUnixDiffTime to create values that are in-range. This avoids any gotchas when then doing comparisons.

Constructors

UnixDiffTime

Fields

• udtSeconds :: !CTime

  Seconds from 1st Jan 1970

• udtMicroSeconds :: !Int32

  Micro seconds (i.e. 10^(-6))

Instances

Eq UnixDiffTime

Methods

(==) :: UnixDiffTime -> UnixDiffTime -> Bool

(/=) :: UnixDiffTime -> UnixDiffTime -> Bool

Ord UnixDiffTime

Methods

compare :: UnixDiffTime -> UnixDiffTime -> Ordering

(<) :: UnixDiffTime -> UnixDiffTime -> Bool

(<=) :: UnixDiffTime -> UnixDiffTime -> Bool

(>) :: UnixDiffTime -> UnixDiffTime -> Bool

(>=) :: UnixDiffTime -> UnixDiffTime -> Bool

max :: UnixDiffTime -> UnixDiffTime -> UnixDiffTime

min :: UnixDiffTime -> UnixDiffTime -> UnixDiffTime

Show UnixDiffTime

Methods

showsPrec :: Int -> UnixDiffTime -> ShowS

show :: UnixDiffTime -> String

showList :: [UnixDiffTime] -> ShowS

diffUnixTime :: UnixTime -> UnixTime -> UnixDiffTime

Calculating difference between two UnixTime.

>>> UnixTime 100 2000 `diffUnixTime` UnixTime 98 2100
UnixDiffTime {udtSeconds = 1, udtMicroSeconds = 999900}

addUnixDiffTime :: UnixTime -> UnixDiffTime -> UnixTime

Adding difference to UnixTime.

>>> UnixTime 100 2000 `addUnixDiffTime` microSecondsToUnixDiffTime (-1003000)
UnixTime {utSeconds = 98, utMicroSeconds = 999000}

secondsToUnixDiffTime :: Integral a => a -> UnixDiffTime

Creating difference from seconds.

>>> secondsToUnixDiffTime 100
UnixDiffTime {udtSeconds = 100, udtMicroSeconds = 0}

microSecondsToUnixDiffTime :: Integral a => a -> UnixDiffTime

Creating difference from micro seconds.

>>> microSecondsToUnixDiffTime 12345678
UnixDiffTime {udtSeconds = 12, udtMicroSeconds = 345678}

>>> microSecondsToUnixDiffTime (-12345678)
UnixDiffTime {udtSeconds = -12, udtMicroSeconds = -345678}

Translating time

fromEpochTime :: EpochTime -> UnixTime

From EpochTime to UnixTime setting utMicroSeconds to 0.

toEpochTime :: UnixTime -> EpochTime

From UnixTime to EpochTime ignoring utMicroSeconds.

fromClockTime :: ClockTime -> UnixTime

From ClockTime to UnixTime.

toClockTime :: UnixTime -> ClockTime

From UnixTime to ClockTime.