is there a way to get calendarweek of an NSDate according ISO 8601. I think:
Datecomponents *dateComponents = [cal components:(NSWeekOfYearCalendarUnit ) fromDate: testDate ];
int calandarWeek = [dateComponents weekOfYear];
uses a different algorithm.
ISO definition: CW1 is the first week in the year containing 4 day, CW start on Mondays
I found out. It´s possible to configure the NSCalender:
[cal setFirstWeekday:2]; //week starts on Monday
[cal setMinimumDaysInFirstWeek:4]; //first week in the year containing 4 day