time-1.4: A time library

Safe HaskellSafe-Infered

Data.Time.Clock.UTC

Contents

Synopsis

UTC

UTC is time as measured by a clock, corrected to keep pace with the earth by adding or removing occasional seconds, known as "leap seconds". These corrections are not predictable and are announced with six month's notice. No table of these corrections is provided, as any program compiled with it would become out of date in six months.

If you don't care about leap seconds, use UTCTime and NominalDiffTime for your clock calculations, and you'll be fine.

data UTCTime Source

This is the simplest representation of UTC. It consists of the day number, and a time offset from midnight. Note that if a day has a leap second added to it, it will have 86401 seconds.

Constructors

UTCTime 

Fields

utctDay :: Day

the day

utctDayTime :: DiffTime

the time from midnight, 0 <= t < 86401s (because of leap-seconds)

data NominalDiffTime Source

This is a length of time, as measured by UTC. Conversion functions will treat it as seconds. It has a precision of 10^-12 s. It ignores leap-seconds, so it's not necessarily a fixed amount of clock time. For instance, 23:00 UTC + 2 hours of NominalDiffTime = 01:00 UTC (+ 1 day), regardless of whether a leap-second intervened.