NSDateComponents *comps = [[NSDateComponents alloc] init];

[comps setDay:6];

[comps setMonth:5];

[comps setYear:2004];

NSCalendar *gregorian = [[NSCalendar alloc]

initWithCalendarIdentifier:NSGregorianCalendar];

NSDate *date = [gregorian dateFromComponents:comps];

[comps release];

NSDateComponents *weekdayComponents =

[gregorian components:NSWeekdayCalendarUnit fromDate:date];

int weekday = [weekdayComponents weekday];