unix-time-0.3.8: Unix time parser/formatter and utilities

Safe HaskellNone
LanguageHaskell2010

Data.UnixTime

Contents

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

Getting time

getUnixTime :: IO UnixTime Source #

Get current 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. utMicroSeconds is always set to 0.

parseUnixTimeGMT :: Format -> ByteString -> UnixTime Source #

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 Source #

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 Source #

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 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

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