Question

I calculate number of days between two dates:

NSDateComponents *datesDiff = [calendar components: NSDayCalendarUnit 
                                          fromDate: someDate
                                            toDate: currentDate
                                           options: 0];

But this method has one disadvantage – it doesn’t take in account time zone.
So, for example, if I’m in +2GMT and local time is 1:00AM, current date is yesterday.

How to compare dates in specified time zone (without ‘hacking’)?

PS: Preventing answers with calculation of time difference, I need difference of actual days:

• yesterday 23:00 vs. today 1:00 – 1 day
• yesterday 1:00 vs. today 23:00 – 1 day

• today 1:00 vs. today 23:00 – 0 days

• (all this in current time zone)

Answer 1

I don’t know if it meets your criteria of not being hacky, but a fairly simple way seems to be defining a GMT adjusted date something like this:

NSDate *newDate = [oldDate dateByAddingTimeInterval:(-[[NSTimeZone localTimeZone] secondsFromGMT])

See this question for more details.