UTCTime is:exact

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.

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.

Coördinated universal time (UTCTime) is the most commonly used standard for civil timekeeping. It is synchronised with TAI (AbsoluteTime) and both tick in increments of SI seconds, but UTC includes occasional leap-seconds to keep it close to UT1 (UniversalTime).

> utcTime # UTCView (gregorian # YearMonthDay 2016 1 15) (timeOfDay # TimeOfDay 12 34 56.78)
2016-01-15 12:34:56.78 UTC

> UTCTime (gregorian # YearMonthDay 2016 1 15) (timeOfDay # TimeOfDay 12 34 56.78)
2016-01-15 12:34:56.78 UTC

> mkUTCTime 2016 1 15  12 34 56.78
2016-01-15 12:34:56.78 UTC

UTCTime is an AffineSpace with NominalDiffTime as its Diff. See Data.Thyme.Docs#spaces for details.

> let t0 = mkUTCTime 2016 1 15  23 59 0
> let t1 = mkUTCTime 2016 1 16  00  1 1
> let dt = t1 .-. t0
> dt
121s :: NominalDiffTime

> t1 .+^ dt
2016-01-16 00:03:02 UTC

> t1 .+^ 3 *^ dt
2016-01-16 00:07:04 UTC

To decompose a UTCTime into a separate Day and time-of-day, use utcTime. To convert to a local time zone, see zonedTime or utcLocalTime.

Notes

Internally UTCTime is just a 64-bit count of microseconds since the Modified Julian Day epoch, so (.+^), (.-.) et cetera ought to be fast. UTCTime cannot represent leap seconds. If leap seconds matter, use AbsoluteTime from Data.Thyme.Clock.TAI instead, along with absoluteTime' and UTCView for presentation.