Calculating the number of days between two dates in Objective-C

Question

Possible Duplicate:
How can I compare two dates, return a number of days

I have two dates (as NSString in the form "yyyy-mm-dd"), for example:

NSString *start = "2010-11-01"; NSString *end = "2010-12-01"; 

I'd like to implement:

- (int)numberOfDaysBetween:(NSString *)startDate and:(NSString *)endDate {  } 

Answer 1

NSString *start = @"2010-09-01"; NSString *end = @"2010-12-01";  NSDateFormatter *f = [[NSDateFormatter alloc] init]; [f setDateFormat:@"yyyy-MM-dd"]; NSDate *startDate = [f dateFromString:start]; NSDate *endDate = [f dateFromString:end];  NSCalendar *gregorianCalendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian]; NSDateComponents *components = [gregorianCalendar components:NSCalendarUnitDay                                                     fromDate:startDate                                                       toDate:endDate                                                      options:0]; 

components now holds the difference.

NSLog(@"%ld", [components day]);