Hi Simon, http://hackage.haskell.org/package/lens-datetime-0.2/docs/Data-Time-Lens.html
Read the top of the page. aDay = fromGregorian 2013 08 22 aLocal = LocalTime aDay (TimeOfDay 13 45 28) aUTC = UTCTime aDay 7458.9 >>> aLocal ^. years 2013 >>> aUTC ^. months 8 >>> aDay ^. days 22 >>> aLocal & time .~ midnight 2013-08-22 00:00:00 >>> aUTC & days .~ 1 & months .~ 1 2013-01-01 02:04:18.9 UTC >>> aLocal & hours +~ 1 -- But see the note below! 2013-08-22 14:45:28 >>> aLocal & flexDT.months +~ 12 2014-08-22 13:45:28 >>> aUTC & flexDT.days +~ 100 2013-11-30 02:04:18.9 UTC >>> aLocal & flexDT.minutes +~ 120 2013-08-22 15:45:28 Gergely _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe