While the RTC on the DS1921G does automatically compensate for leap year, it does not account for daylight savings. You can get around this by selecting the "Synchronize Real-time Clock" in the Start New Mission Window. This will synchronize the device's real-time clock to the PC that you are using. As long as your PC accounts to daylight savings, and you select "Synchronize Real-time Clock," the device will adjust with daylight savings.