Start by disarming your L3000. Type in your master code and then the pound (#) key. Then type (63). This accesses the voice prompt calendar mode, which will proceed to guide you through the rest of date/time programming. You will systematically set the correct hour, AM/PM, the minute, month, day, and year. At anytime, press (#) to have the voice prompt repeat a step. One minute of inactivity will cause the system to automatically exit date/time programming mode. Pressing the "Off" key will send you back to the last menu in case you need to fix a mistake.