add NSTimeInterval to NSDate in cocoa

Question

I've got a NSDate that represents a specific time. The format of that date is hhmmss. I want to add an NSInterval value (specified in seconds) to that time value.

Example:

NSDate =         123000
NSTimeInterval = 3600

Added together = 133000

What is the best way to do this?

Solution 1

Have you seen the Dates and Times Programming Topics for Cocoa manual?

Basically you need to convert your time into an NSDate. To convert a string to a date you use the NSDateFormatter class or maybe NSDateComponents if you already know the hours, minutes and seconds.

Your NSTimeInterval is just a double (i.e., 3600.0).

Then you use the dateByAddingTimeInterval method of NSDate to add the number of seconds to the time.

NSDate* newDate = [oldDate dateByAddingTimeInterval:3600.0];

You can then use either NSDateFormatter or NSDateComponents to get the new time back out again.

Solution 2

addTimeInterval is now deprecated. Try using dateByAddingTimeInterval instead.

Solution 3

// This will set the time when your view appears it will also
// set the time if you want to retrieve from it.
-(void)viewDidAppear:(BOOL)animated
{
     //Create todays date
     NSDate *duedate = [NSDate date];
     //Add how ever many days you could write 86400*numbe_of_days days 86400/24 for an hour
     //Then simply reassign the variable or use a different one.
     duedate = [duedate dateByAddingTimeInterval:86400];  //I add one day
     [datePicker setDate:duedate animated:YES]; //Animate yes will show your pickers moving
     [datePicker setMinimumDate:duedate]; //Set minimum date.
}