calculating number of days, nsdate, ios

Question

The way I am calculating the difference between of 2 dates is

NSCalendar *calendar            =   [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];

NSDateComponents *nowAndEnd     =   [calendar components:NSMonthCalendarUnit|
                                                        NSDayCalendarUnit|
                                                        NSMinuteCalendarUnit
                                                fromDate:now
                                                  toDate:end
                                                 options:0];


NSLog(@"nowAndEnd's day is %d",nowAndEnd.day);
NSLog(@"nowAndEnd's month is %d",nowAndEnd.month);

And I am getting back is

 nowAndEnd's day is 15
 nowAndEnd's month is 1

Question is how can I compute the days from those info. I am asking because some of months have 30 days and some of them have 31...

"how can I compute the days" - you **just did that,** didn't you. — , Mar 14 '13 at 20:25
Possible duplication of: http://stackoverflow.com/questions/4575689/objective-c-calculating-the-number-of-days-between-two-dates — Blake Schwendiman, Mar 14 '13 at 20:28
the day is 14 but you also have a month so the total days should be 1 *30 + 15 or 1*31 + 15 or even 1*28 + 15 — tranvutuan, Mar 14 '13 at 20:28

score 3 · Accepted Answer · answered Mar 14 '13 at 20:34

3

What you did is correct, but if you want the calculation to be performed on days only, just use the NSDayCalendarUnit alone:

NSDateComponents *nowAndEnd    =   [calendar components:NSDayCalendarUnit
                                                fromDate:now
                                                  toDate:end
                                                 options:0];

The answer will be directly calculated to the number of days.

answered Mar 14 '13 at 20:34

viggio24

12,316
5
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thanks for pointing it out. However, the day I am getting is shorter than the actually total days, example is the actually total days is 47, i am getting 46... – tranvutuan Mar 14 '13 at 20:41
This is strange. Consider in any case that in the calculation the starting day is not included. So from Jan. 1 to Feb. 5 you have (31-1)+5=35 days and not 36. – viggio24 Mar 14 '13 at 20:49

calculating number of days, nsdate, ios

1 Answers1