Adding days to NSDate

int daysToAdd = 1;

NSDateComponents *components = [[[NSDateComponents alloc] init] autorelease];

[components setDay:daysToAdd];

// create a calendar

NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];

NSDate *newDate = [gregorian dateByAddingComponents:components toDate:datePicker.date options:0];

Adding days to NSDate

iPhone SDK Tips & Tricks

NSDate *now = [NSDate date];
int daysToAdd = 50; // or 60 :-)

// set up date components
NSDateComponents *components = [[[NSDateComponents alloc] init] autorelease];
[components setDay:daysToAdd];

// create a calendar
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];

NSDate *newDate2 = [gregorian dateByAddingComponents:components toDate:now options:0];
NSLog(@"Clean: %@", newDate2);