A small handheld sun dial. A lid opens with a glass ring to project the sun onto the dial. Hold the glass ring at due south and the shadow cast on the dashes will give you the exact time of day. If you concentrate on that time it will remain stopped for one action. Granting you a free attack during combat. It can also be used to take that action to take the disengage action without any attacks of opportunity being created. 

You can use this once per day at any time except on the turn of a creature attacking you. 

As soon as you have have completed your action time restarts where it was.

Notes: You must check the hour every hour as the sun moves around the small clock face for a full day.