I'm trying to write an application to deal with turning wall times back and forth to system times. I don't really understand how to get around this one issue with Daylight Savings Time.
In Los Angeles, at 2:00 AM on 11/7/10, the clocks fell back to 1:00 AM. There were "two different" 1:00 AMs.
I am giving the calendar the system time of the first 1:00 AM, but the components being returned seem to represent the second 1:00 AM. How do I reliably specify arbitrary wall times to the system without having this issue?
In Los Angeles, at 2:00 AM on 11/7/10, the clocks fell back to 1:00 AM. There were "two different" 1:00 AMs.
Code:
NSDate *date = [NSDate dateWithTimeIntervalSinceReferenceDate: 310809600];
NSLog(@"%f", [date timeIntervalSinceReferenceDate]); // This is the "first" 1:00 AM
NSDateComponents *components = [[NSCalendar currentCalendar] components: (NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSHourCalendarUnit) fromDate: date];
date = [[NSCalendar currentCalendar] dateFromComponents: components];
NSLog(@"%f", [date timeIntervalSinceReferenceDate]); // This is the "second" 1:00 AMI am giving the calendar the system time of the first 1:00 AM, but the components being returned seem to represent the second 1:00 AM. How do I reliably specify arbitrary wall times to the system without having this issue?