How do I Increment an NSDate object in Objective-C

Question

I want to take the next day by giving the current date The code i used as follows

+(NSDate *)getForDays:(int)days fromDate:(NSDate *) date {
    NSTimeInterval secondsPerDay = 24 * 60 * 60 * days;
        return [date addTimeInterval:secondsPerDay];
} 

this works fine but when the daylight saving enabled this leads to errors. How can I make this work when daylight saving is enabled.

Answer 1

As you have found, what you have now is pretty error-prone. Not only can it trip up over a daylight savings change, but also what if your user has a non-gregorian calendar? Then, days are not 24 hours long.

Instead, use NSCalendar and NSDateComponents which were exactly designed for this:

+ (NSDate *)getForDays:(int)days fromDate:(NSDate *)date
{
    NSDateComponents *components= [[NSDateComponents alloc] init];
    [components setDay:days];

    NSCalendar *calendar = [NSCalendar currentCalendar];
    return [calendar dateByAddingComponents:components toDate:date options:0];
}

Answer 2

Use NSCalendar to perform calculations like this. Not only is it more likely to work, but your code will be clearer.