To change the time on a Fitbit, you'll need to adjust the time zone setting for your device on the Fitbit mobile app or ...
To reset your Fitbit Alta, you'll need to repeatedly press a button on your charger. But to wipe your data, you'll need to ...
Restart > clean connections > use a different charger > replace the cable > bring the phone closer. Check Bluetooth connection > disconnect other Bluetooth devices > restart Fitbit app > check for ...