Worst Post Title ever! This one took me a bit to figure out so I thought I’d post it in case anyone else out there had troubles. I wanted to get an NSDate for a specific day of the week and time from an existing NSDate object in order to create a countdown timer.

This example will get you the NSDate for the following Monday at 8am:

NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[gregorian setLocale:[NSLocale currentLocale]];

NSDateComponents *nowComponents = [gregorian components:NSYearCalendarUnit | NSWeekCalendarUnit | NSHourCalendarUnit | NSMinuteCalendarUnit | NSSecondCalendarUnit fromDate:today];

[nowComponents setWeekday:2]; //Monday
[nowComponents setWeek: [nowComponents week] + 1]; //Next week
[nowComponents setHour:8]; //8a.m.
[nowComponents setMinute:0];
[nowComponents setSecond:0];

NSDate *beginningOfWeek = [gregorian dateFromComponents:nowComponents];

Now that you have the new NSDate, you can calculate the difference between the two by using fromDate.