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