Getting date from weekday - ios

Question

I'm doing this app where the user inputs some days (Using UITableView, monday - sunday).
I then need the app to figure out which dates this matches with. Say it's the user sits on sunday the 15th and chooses monday and tuesday. The app will figure out the dates are monday 16th and tuesday 17th.
How would one go about that using NSDate and such? I know how to find a weekday using the date, but I want the opposite.
Of course it has to be the closest days, like not finding monday the 23rd, but finding 16th.
Hope that makes sense. :-)

Answer 1

A direct method, without using a loop:
NSUInteger targetWeekday = ...; // 1 = Sunday, 2 = Monday, ...
// Date components for today:
NSCalendar *cal = [NSCalendar currentCalendar];
NSDate *now = [NSDate date];
NSDateComponents *comp = [cal components:NSYearCalendarUnit|NSMonthCalendarUnit|NSDayCalendarUnit|NSWeekdayCalendarUnit
fromDate:now];
// Adjust components for target weekday:
if (targetWeekday >= comp.weekday) {
comp.day += (targetWeekday - comp.weekday);
} else {
comp.day += (targetWeekday + 7 - comp.weekday); // Assuming 7 days per week.
}
comp.weekday = targetWeekday;
// And back to NSDate:
NSDate *targetDate = [cal dateFromComponents:comp];
Remark:
if (targetWeekday >= comp.weekday) {
comp.day += (targetWeekday - comp.weekday);
} else {
comp.day += (targetWeekday + 7 - comp.weekday); // Assuming 7 days per week.
}
can be replaced by the shorter, equivalent code
comp.day += (targetWeekday + 7 - comp.weekday) % 7;

Answer 2

You can do it by following a simple procedure:
Start with an NSDate that represents today
Get the day of the week from it (here is how it is done)
If the day of the week matches what's in the selected UITableViewCell, you are done.
Otherwise, add one day to NSDate (here is how it is done), and go back to step 2.