How Do I Change From Military Time on My Armitron Watch?. Some of the company's watches display military time, which uses a 24-hour clock. Pressing a few buttons will change the mode on any Armitron watch. Press the top left button on your watch once. The seconds should begin flashing. Press the lower left button six times until the 12/24-hour format appears.
Press the RESET button (A) to tab through seconds, minutes, hour. The ST/STP button (C) scrolls through the number choices. When selecting the hour, if you want 12hr.