Adde Nilsson wrote: >>> Ok, do you know of any way to add/subtract without converting to UTC and >>> back?
Brandon Allbery wrote: >> I'm not sure I'd do that in any environment, since usually libraries don't >> deal with the result crossing a daylight/summer time change (and those that >> do, surprise surprise, normalize to UTC). > Didn't know, thanks. > Back in Haskell land my conclusion is that if you're planning on doing pure > date calculations you have to pass a TimeZone as well. For that to work near clock changes, you need to have the latest summer time/DST policies coded in your app so that you can pass the correct TimeZone. You also need hand-coded logic to handle clock times that occur twice, and clock times that never occur at all, due to changes of clock. <shameless-plug> An alternative is to use the timezone-series package. Your timezone series knows about the latest clock change policies if you create it from an up-to-date Olson timezone file using the timezone-olson package. http://hackage.haskell.org/package/timezone-series http://hackage.haskell.org/package/timezone-olson </shameless-plug> Regards, Yitz _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe