Question

i have an NSDate object from an old date which i am getting from my DB. Now i need to set my UIDatePicker date to current date but with hour and minute value from my stored NSDate object which i have got from my DB.

So how to extract hour and minute from old date and set it to current UIDatePicker NSdate.

Thanks

Answer 1

Since a NSDate can’t be changed after it’s initialization, you have to recreate it:

To get the hour and minute component of the NSDate use NSCalendar:

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *dateComponents = [gregorian components:(NSHourCalendarUnit  | NSMinuteCalendarUnit | NSSecondCalendarUnit) fromDate:yourOriginalDateHere];
NSInteger hour = [dateComponents hour];
NSInteger minute = [dateComponents minute];
NSInteger second = [dateComponents second];

Then you can create a new NSDate (also using NSCalendar):

NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *dateComponents = [gregorian components:(NSYearCalendarUnit  | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:[NSDate date]]; //[NSDate date] is the current date
[dateComponents setHour:hour];
[dateComponents setMinute:minute];
[dateComponents setSecond:second];
NSDate *newDate = [gregorian dateFromComponents:dateComponents];