Safe Haskell	None
Language	Haskell2010

Data.UnixTime

Contents

Data structure
Getting time
Parsing and formatting time
Format
Difference time
Translating time

Synopsis

Data structure

data UnixTime Source

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 Source
Ord UnixTime Source
Show UnixTime Source
Storable UnixTime Source
Binary UnixTime Source

Getting time

getUnixTime :: IO UnixTime Source

Getting UnixTime from OS.

Parsing and formatting time

parseUnixTime :: Format -> ByteString -> UnixTime Source

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.

parseUnixTimeGMT :: Format -> ByteString -> UnixTime Source

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

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

formatUnixTime :: Format -> UnixTime -> IO ByteString Source

Formatting UnixTime to ByteString in local time. This is a wrapper for strftime_l().

formatUnixTimeGMT :: Format -> UnixTime -> ByteString Source

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

>>> formatUnixTimeGMT webDateFormat $ UnixTime 0 0
"Thu, 01 Jan 1970 00:00:00 GMT"

Format

type Format = ByteString Source

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

webDateFormat :: Format Source

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 Source

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 Source

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 Source
Ord UnixDiffTime Source
Show UnixDiffTime Source

diffUnixTime :: UnixTime -> UnixTime -> UnixDiffTime Source

Calculating difference between two UnixTime.

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

addUnixDiffTime :: UnixTime -> UnixDiffTime -> UnixTime Source

Adding difference to UnixTime.

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

secondsToUnixDiffTime :: Integral a => a -> UnixDiffTime Source

Creating difference from seconds.

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

microSecondsToUnixDiffTime :: Integral a => a -> UnixDiffTime Source

Creating difference from micro seconds.

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

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

Translating time

fromEpochTime :: EpochTime -> UnixTime Source

From EpochTime to UnixTime setting utMicroSeconds to 0.

toEpochTime :: UnixTime -> EpochTime Source

From UnixTime to EpochTime ignoring utMicroSeconds.

fromClockTime :: ClockTime -> UnixTime Source

From ClockTime to UnixTime.

toClockTime :: UnixTime -> ClockTime Source

From UnixTime to ClockTime.