Get NSDate from week and day

Question

I am trying to get an NSDate from a day and week post to today.

E.g. week = 2 and day = 4, which would be thursday in two weeks from now (given the week starts on Monday).

I tried a bunch of different things using NSCalendar and NSDateComponents, but nothing came close. Searched a bit as well, but haven't found any other topic regarding my problem.

The last thing I tried was the following:

- (NSDate *)getDateForIndexPath:(NSIndexPath *)indexPath
{
    int week = ((indexPath.row / 7) % 5);
    int day = (indexPath.row % 7);

    NSDate *referenceDate = [NSDate date];

    NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
    [calendar setLocale:[[NSLocale alloc] initWithLocaleIdentifier:@"es_ES"]];
    [calendar setTimeZone:[NSTimeZone localTimeZone]];

    NSDateComponents *dateComponents = [calendar components:(NSYearCalendarUnit|NSMonthCalendarUnit | NSWeekCalendarUnit |NSWeekdayCalendarUnit) fromDate:referenceDate];
    [dateComponents setWeekday:day];
    [dateComponents setWeek:dateComponents.week+(week-1)];
    [dateComponents setWeek:dateComponents.week];

    NSDate *followingDate = [calendar dateFromComponents:dateComponents];

    NSLog(@"Week: %d - Day: %d", week, day);
    NSLog(@"followingDate: %@", followingDate);

    return followingDate;
}

This gave me the same date over and over again, besides the fact that it sees day 0 as sunday:

2014-04-08 00:02:33.706 TVSports[79878:60b] Week: 1 - Day: 0
2014-04-08 00:02:33.707 TVSports[79878:60b] followingDate: 2014-04-11 22:00:00 +0000
2014-04-08 00:02:33.708 TVSports[79878:60b] Week: 1 - Day: 1
2014-04-08 00:02:33.708 TVSports[79878:60b] followingDate: 2014-04-05 22:00:00 +0000
2014-04-08 00:02:33.709 TVSports[79878:60b] Week: 1 - Day: 2
2014-04-08 00:02:33.709 TVSports[79878:60b] followingDate: 2014-04-06 22:00:00 +0000
2014-04-08 00:02:33.710 TVSports[79878:60b] Week: 1 - Day: 3
2014-04-08 00:02:33.710 TVSports[79878:60b] followingDate: 2014-04-07 22:00:00 +0000

Answer 1

You can do this to get the Thursday in two weeks:

typedef NS_ENUM(NSUInteger, WeekDay){
    WeekDaySunday = 1,
    WeekDayModay,
    WeekDayTuesday,
    WeekDayWensday,
    WeekDayThursday,
    WeekDayFriday,
    WeekDaySaturday
};


NSDate *now = [NSDate date];
NSDate *beginOfThisWeek;
NSCalendar *cal = [NSCalendar currentCalendar];
[cal setFirstWeekday:WeekDayModay];
[cal rangeOfUnit:NSWeekCalendarUnit // get the beginning of this week
       startDate:&beginOfThisWeek   // save the beginning to this variable
        interval:NULL               // we do not care for the weeks length
         forDate:now];
NSDateComponents *twoWeeks = [[NSDateComponents alloc] init];
twoWeeks.week = 2;
twoWeeks.day = WeekDayThursday - WeekDaySunday -1 ; // we need the difference between thursday and the beginning of the week

NSDate *thurdayInTwoWeeks = [cal dateByAddingComponents:twoWeeks 
                                                 toDate:beginOfThisWeek
                                                options:0];