Thyme is a rewrite of the fine
time library, with a particular focus
on performance for applications that make heavy use of timestamps. For
UTCTime is represented with μs precision as an
Int64, which gives a usable range from
19:59:05.224192 UTC to
294135-11-26 04:00:54.775807 UTC in the future.
On platforms where
Int is 64-bits wide, types with an
can be used as
EnumMap wrapper provided by
http://hackage.haskell.org/package/enummapset-th. In any case the
instances are much faster, if you must use
Data.Thyme.Time is a drop-in compatibility module for existing code.