Panic, try this.
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
formatter.timeStyle = NSDateFormatterNoStyle;
formatter.dateFormat = @"MM/dd/yyyy";
NSDate *intialTime= [formatter dateFromString:@"12/11/2005"];
NSDate *presentDate = [NSDate date];
NSTimeInterval timeInterval = [presentDate timeIntervalSinceDate:intialTime];
int seconds = (int)ceil(timeInterval);
int mins = seconds / 60;
NSLog(@"Time interval in Mins:%d",mins);