This is a length of time, as measured by UTC. It has a precision of
10^-12 s.
Conversion functions such as
fromInteger and
realToFrac
will treat it as seconds. For example,
(0.010 ::
NominalDiffTime) corresponds to 10 milliseconds.
It has a precision of one picosecond (= 10^-12 s). Enumeration
functions will treat it as picoseconds.
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.