Return the integer representation of the required unit for the given date Note: this functions assumes that the current calendar is set to Gregorian and takes as units year, month,day, hour,minute and second.

[Date]UnitForDate.m

// Return integer representation of the required unit for the given date
// Note: It assumes that the current calendar is set to Gregorian
+ (NSInteger)unit:(NSCalendarUnit)unit forDate:(NSDate*)date{
    
    // Get the calendar
    NSCalendar *calendar = [[NSCalendar alloc]initWithCalendarIdentifier:NSGregorianCalendar];
    [calendar setTimeZone:[NSTimeZone defaultTimeZone]];
    
    // Get the component
    NSDateComponents *componets = [calendar components:unit fromDate:date];
    
    // Not Available in iOS :(
    //return [componets valueForComponent:unit];
    
    
    switch (unit) {
            
        case NSCalendarUnitDay:
            return [componets day];
            break;
            
        case NSMonthCalendarUnit:
            return [componets month];
            break;
            
        case NSYearCalendarUnit:
            return [componets year];
            break;
            
        case NSHourCalendarUnit:
            return [componets hour];
            break;
            
        case NSMinuteCalendarUnit:
            return [componets minute];
            break;
            
        case NSSecondCalendarUnit:
            return [componets second];
            break;
            
        default:
            NSLog(@"This Calendar Unit is not supported in the function %s", __FUNCTION__);
            return INT_MAX;
            break;
    }
}