User manual link is below. To change it from military time to regular do the following: Press the mode button (lower left) once - the top right display should change from temperature to day of week. Then press the start button (upper right). That will change the time to 12h.

Can someone tell me how to switch between the 12 and 24 hr mode?
thanks!

I found no help at this site, but here are links that will hopefully help people in the future:
found a set of manuals here:
http://www.gsi-usa.com/instructions/
and the one for my watch here:
http://www.gsi-usa.com/instructions/AD32397-CR-EN.pdf

I don't know why the "Member Provided Link" does not work for me, so if the one that they add when I post goes screwy then it is a problem of ManualsOnline.com