Daylight Savings Time
I have put together some code from various sites such as this one: http://blog.coriolis.ch/2009/02/20/relative-date-to-now/ Basically I would like to display records for a week duration but I am unsure how to handle daylight savings time. Is there a way to see if daylight savings time has or will occur? The logic of my code is to display from Sunday to Saturday zeroing out the current time to midnight but it does not appear to work well with daylight savings which then sees one day overlapping another. Anyone see or know of any code to deal with daylight savings time? Thanks Greg ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Daylight Savings Time
On Apr 15, 2009, at 11:53 AM, Greg Robertson wrote: I have put together some code from various sites such as this one: http://blog.coriolis.ch/2009/02/20/relative-date-to-now/ Basically I would like to display records for a week duration but I am unsure how to handle daylight savings time. Is there a way to see if daylight savings time has or will occur? The logic of my code is to display from Sunday to Saturday zeroing out the current time to midnight but it does not appear to work well with daylight savings which then sees one day overlapping another. Anyone see or know of any code to deal with daylight savings time? I don't have specific code examples. But, generally: -- use something like NSTimeZone's "isDaylightSavingTime" or "isDaylightSavingTimeForDate" to know whether a specific date/time is in fact a daylight saving time -- Convert your date/time information to UTC for actual processing, using the DST information as appropriate; depending on where the data comes from this may or may not result in ambiguity during the Fall transition...you may have to ask the user whether the local time is before or after the transition time, or just accept the overlap in the results. But, if you can get the input to include the exact time zone (e.g. "PST" versus "PDT") and/or the raw UTC offset, this isn't an issue. -- don't forget to use the correct term: "daylight saving time", no plural. :) Pete ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Daylight Savings Time
Greg Robertson wrote: Basically I would like to display records for a week duration but I am unsure how to handle daylight savings time. Is there a way to see if daylight savings time has or will occur? If you want to see whether a DST switch happens during a given interval, just subtract the dates. If the NSTimeInterval doesn't come out to some multiple of 24 hours, a switch happened. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: Daylight Savings Time
There is also [NSTimeZone nextDaylightSavingTimeTransition] and [NSTimeZone nextDaylightSavingTimeTransitionAfterDate:], both available in 10.5 or later. Deborah Goldsmith Apple Inc. golds...@apple.com On Apr 15, 2009, at 2:41 PM, Gregory Weston wrote: Greg Robertson wrote: Basically I would like to display records for a week duration but I am unsure how to handle daylight savings time. Is there a way to see if daylight savings time has or will occur? If you want to see whether a DST switch happens during a given interval, just subtract the dates. If the NSTimeInterval doesn't come out to some multiple of 24 hours, a switch happened. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/goldsmit%40apple.com This email sent to golds...@apple.com ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
