This is the result of a discrepancy between the Tablo’s time zone and your local time zone. The Tablo grabs its time zone information from the device you use to run a channel scan on the Tablo.
Make sure your device(s) all have the right time zone information on them, and then open up the Tablo app and run a new channel scan: Settings > Edit channel lineup > Rescan> Add to guide.
Keep in mind that if you have any kind of VPN or IP altering/masking service, this will interfere with the time zone being set. If you continue to have issues, set us a ticket and we’ll take care of you.