Get Week Start date returning next week day if today is sunday

Question

i have a function which returns weekdays by passing any specific day, in my app , monday will be the week start day, it works fine except when settings current day to sunday, in this case the function is returning next weekdays ,

+(NSMutableArray*) getWeekDatesList :(NSDate*) date {
    @autoreleasepool {

        NSDate *startingDateOfWeek = [self getWeekStartDateWithDate:date];
        return [self getWeekDatesListWithStartDate:startingDateOfWeek];
    }  
},

and function to get week start date is,

+(NSDate*) getWeekStartDateWithDate:(NSDate*) date{
    @autoreleasepool {

        NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
        [gregorian setLocale:[NSLocale currentLocale]];
        [gregorian setFirstWeekday:2]; // 2 monday

        [gregorian setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT"]];
        NSDateComponents *components = [gregorian components:NSWeekdayCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekOfYearCalendarUnit |NSWeekCalendarUnit fromDate:date];

        int value =([components day]-([components weekday]-2));

        [components setDay:value];
        [components setHour:0];
        [components setMinute:0];
        [components setSecond:0];

        NSDate *beginningOfWeek = [gregorian dateFromComponents:components];
        return beginningOfWeek;
    }
}

Example:

settings today as Sunday April 20 2014, am getting week start date as April 21 2014, but expected week start date is April 13 2014

how can i make it work correctly even when current day is set to sunday ?

Thanks

Answer 1

In your calculation you would have to check if [components weekday] is less or greater than 2 (Monday) and modify the components accordingly to get the previous Monday.

But you can simplify the calculation to:

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
// [gregorian setLocale:[NSLocale currentLocale]]; (This is the default.)
[gregorian setFirstWeekday:2]; // 2 = Monday
[gregorian setTimeZone:[NSTimeZone timeZoneWithAbbreviation:@"GMT"]];

NSDate *beginningOfWeek;
[gregorian rangeOfUnit:NSWeekCalendarUnit startDate:&beginningOfWeek interval:NULL forDate:date];

This gives 2014-04-14 00:00:00 +0000 (a Monday) as expected.

Remark: You should check if you really want to set the time zone to GMT. If you don't set a time zone then you will get the beginning of the week according to your local time zone.