I want to have a countdown (minutes/seconds) that can be set by the user to update a UILabel. I know how to update the UILabel, but I would like to know the most efficient way to have a countdown for anything under, let's say, 15 minutes. How would I go about doing this? Thanks! Please Register or Log in to view images EDIT: I would prefer it to show milliseconds, if possible.\ EDIT 2: I don't want it to be like "enter a date and see how many minutes". I want it to be more like the timer in the Clock application; the user sets the length of the countdown.