AppleScript (or swift) add hours to time - swift

Question

I'm trying to add 8Hours to a date (from the clipboard)
set date1 to the clipboard
set newdate to date1 + (8 * hours)
display dialog "Purchases were downloaded at " & newdate buttons {"OK"} default button 1
But this is not working as expected, I'm having the error
Can’t make "06/22/2015 08:15:27 " into type number.

Answer 1

You need to pick the hours as an individual variable, like shown below:
set currentDate to current date
set newHour to ((hours of currentDate) + 8)
You can also use this for days, minutes and seconds.
This will work. You can then use the variables to construct a new date to be used in the display dialog.
PS. Don't forget to change the day if the newHour variable is bigger than 24 hours.
EDIT
Setting a date to the clipboard can be done like this:
set currentDate to current date
set the clipboard to currentDate as Unicode text
Getting the current clipboard and adding it to a variable goes like this:
set currentDate to get the clipboard
display dialog currentDate
I hope this helps!

Answer 2

In Swift, you can call dateByAddingTimeInterval on an NSDate object.
The time interval is measured in seconds.
yourDate.dateByAddingTimeInterval(8 * 60 * 60)
If you wanted to add another method to add 8 hours directly, you could define an extension:
extension NSDate {
func addEightHours() -> NSDate {
return self.dateByAddingTimeInterval(8 * 60 * 60)
}
}