Truncate NSDate (Zero-out time)

Question

I want to generate a new NSDate with 0 hours, 0 minutes, and 0 seconds for time. The source date can be any r

Answer 1

Use NSCalendar's rangeOfUnit:startDate:interval:forDate:. This code will choose the day boundary based on the current time zone. If you want a particular time zone, you need to create an NSCalendar and set its time zone appropriately.

- (NSDate*)boundaryForCalendarUnit:(NSCalendarUnit)calendarUnit
{
    NSDate *boundary;
    [[NSCalendar currentCalendar] rangeOfUnit:calendarUnit startDate:&boundary interval:NULL forDate:self];
    return boundary;
}

- (NSDate*)dayBoundary
{
    return [self boundaryForCalendarUnit:NSDayCalendarUnit];
}