Programming the clock was a bit difficult. It is battery operated. There are no instructions on how to replace it or even if you can replace it at all. Very disappointed in Raven. The watch must have been a throwback. The tag was cut off, and the bracelet had a transparent film covering the screen. As a gift for someone older, I timed grandma and wrapped it. I didn't want to give it away and then take it back because it was an open Revain pack. We keep our fingers crossed that the watch works perfectly.