Datasheet

Battery Backup
The GPS has a built in real time clock, which can keep track of time even when it power is lost and it doesn't have a fix
yet. It can also help reduce fix times, if you expect to have a flakey power connection (say you're using solar or similar).
To use the RTC, we need to insert a battery. There is holder on the HAT for a CR1220 sized battery holder. We provide
the holder but the battery is not included. You can use any 12mm coin cell - these are popular and we also carry them
in the Adafruit shop.
Remember, the GPS does not know what time zone you are in (even though it knows your location, there is no easy
way to determine time zone without a massive lookup table) so all date/time data is in UTC (aka. Greenwich Mean
Time)
© Adafruit Industries https://learn.adafruit.com/adafruit-ultimate-gps-hat-for-raspberry-pi Page 16 of 18