A check for PBS
Record the local station name or call sign and check its own schedule. Use the station selection in PBS's supported app or site and compare it with the guide. If another station is selected, change that before troubleshooting the clock.
Check the station edition
Record one programme and its scheduled local time on the broadcaster page. Compare it with the channel label and time displayed in your player.
Check the guide if the live feed works
If the programme matches the live edition but the guide is wrong, confirm the channel mapping before changing the device clock.