title: how to show countdown on uilabel in iphone?
body: <p>i have a uilabel and a uislider on a view. i want to set label's time using slider.range of slider is 00:00:00 to 03:00:00. means 3 hours.and intervel on slider is 0.5 minutes.also how to show.i want the timer runs even if application is closed.</p>