gistfile1.m

// This block is invoked when a row in the table view is chosen.
// The table view lists the weekdays from Mon-Sun, so the desiredWeekday line
// is about converting to a system where Sunday is 1
controller.didSelectObjectBlock = ^(id obj, NSUInteger idx) {
    NSInteger desiredWeekday = (idx + 2) % 7;
        
    // Set self.date to a date corresponding to the nearest chosen
    // weekday in the future
    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    NSDate *today = [NSDate date];
    NSDateComponents *todayComponents = [calendar components:NSWeekdayCalendarUnit fromDate:today];
    NSDateComponents *offsetComponents = [[NSDateComponents alloc] init];
    [offsetComponents setWeekday:0 - ([todayComponents weekday] - desiredWeekday)];
        
    if ([offsetComponents weekday] < 0) {
        // If the offset would make the date in the past, add 7 to get into
        // the following week
        [offsetComponents setWeekday:[offsetComponents weekday] + 7];
    }
  
    this.date = [calendar dateByAddingComponents:offsetComponents toDate:today options:0];
    [offsetComponents release];
    [calendar release];
};