My fitbit is not syncing

No, you do not necessarily need a cell phone to use a Fitbit Inspire. While syncing the Fitbit with a smartphone can enhance its functionality by allowing you to receive notifications and track your data more comprehensively, you can still use the Fitbit Inspire without a smartphone.
To set up and use your Fitbit Inspire, you can follow these general steps:

1. Charge your Fitbit: Plug your charging cable into a USB port or wall adapter and connect it to the charging port on the back of your Fitbit Inspire. Charge it fully before you start using it.
2. Create a Fitbit account: If you don't have one, you will need to create a Fitbit account. You can do this on the Fitbit website or through the Fitbit app on a smartphone or tablet.
3. Set up your Fitbit: Follow the on-screen instructions on your Fitbit device or the Fitbit app to set up your device. This typically involves connecting your Fitbit to your Fitbit account.
4. Wear your Fitbit: Put on your Fitbit Inspire and start tracking your activity, sleep, and other metrics.
5. Sync with your phone or computer (optional): If you have a smartphone or a computer with Bluetooth capabilities, you can sync your Fitbit data with the Fitbit app or Fitbit website to see your stats, set goals, and track your progress more comprehensively.

It syncs with your phone or tablet. It should correct the time after it syncs. Mine does this if I let the battery fully die before charging. Once I sync, it is back to the current time.

Bring your charged fitbit near to the plugged-in dongle or base station. You may need to press your fitbit button or tap it to wake it up. Then, Click the Fitbit Connect icon. Finally, Click Open Main Menu, and then click Sync Now. You may be asked to sign in, after which your fitbit should sync with your account.

https://help.fitbit.com/articles/en_US/Help_article/How-do-I-restart-my-tracker
pick charge hr to see instructions on this model