NSDatePicker timezone weirdness

Question

I have an NSDatePicker in my nib file. In code, I set it's timezone to be the GMT calendar's timezone:

[datePicker setTimeZone:[calendar timeZone]];

I only really care about the time (hours, minutes) on the datepicker which I populate programmatically:

NSDate *anyDate = [NSDate date];
        NSDateComponents *components = [calendar components:(NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit) fromDate:anyDate];
        [components setHour:hours];
        [components setMinute:minutes];
        NSDate *newDate = [calendar dateFromComponents:components];
        [datePicker setDateValue:newDate];

This correctly has the desired effect of setting the date pickers time to the time I want. So if hours is 8 and minutes is 30, the date picker shows 8:30. However, if I type an 8 into the hour field of the date picker it displays as a 3. Something weird is going on with timezones somewhere but I'm not sure where...

Do you have a date formatter attached to the date picker? – jtbandes Aug 27 '11 at 02:02 — jtbandes, Aug 27 '11 at 02:02

score 8 · Answer 1 · answered Aug 27 '11 at 02:09

8

Seems like I'm not the first person to stumble across this issue. The solution, for those who are interested, I found here http://www.cocoabuilder.com/archive/cocoa/305254-nsdatepicker-weirdness-with-time.html. Apparently if you set the timezone of a date picker but not the calendar, you get this issue. The resolution is this:

[datePicker setTimeZone:[calendar timeZone]];
[datePicker setCalendar:calendar];

answered Aug 27 '11 at 02:09

JPC

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Just helped me solve the same problem - thanks for posting your findings! – David Stein Apr 02 '13 at 19:14
Surely simpler and more correct to set the date picker's `locale` to the current locale. – matt Apr 23 '17 at 19:34

NSDatePicker timezone weirdness

1 Answers1