lens-datetime (hackage): The lens-datetime library provides a unified lens based accessors to the various types in Data.Time.Clock, Data.Time.Calendar and Data.Time.LocalTime. This library only tries to make some of the common use-cases convenient, it doesn't aim for completeness. If you want completeness and/or efficiency try the thyme package instead (http://hackage.haskell.org/package/thyme).  Demonstration of basic uses.  You can then do the following:  You can manipulate the date-time values with proper roll-over behavior via the FlexibleDateTime mechanism:
Keywords: bsd3|data|lenses|library