Some enhancements to Data.Time

The following packages are available on Hackage:

timezone-series
In Data.Time, the TimeZone data type does not actually represent an entire timezone. Rather, it only represents a specific clock setting that is used in the timezone, possibly one of several clock settings that may apply at different times. This package introduces a new data type, TimeZoneSeries, that represents an entire timezone with all of its possible clock settings. It also provides more reliable variants of some functions in Data.Time that rely upon information about a timezone.
Hackage: http://hackage.haskell.org/package/timezone-series
Darcs repo:  http://code.haskell.org/time-ng/timezone-series
timezone-olson
A parser and renderer for binary Olson timezone data files. Functions are provided to convert Olson data to TimeZoneSeries.
Hackage: http://hackage.haskell.org/package/timezone-olson
Darcs repo:  http://code.haskell.org/time-ng/timezone-olson