The Tablo grabs its time zone information from the device you use to run a channel scan. You can fix this by running a new scan on your Tablo.
First, make sure you're using a device using the correct time zone. Next, connect to the Tablo app and follow these steps:
Settings > Edit location > Use Current > Begin Channel Scan > Add to guide. This will reset your Tablo's local time zone to match the one being used on the device running the channel scan. Try and schedule a new recording to verify the change has been made.
Note: if you have any kind of active VPN, or if the date and time settings on your device are wrong, the Tablo will not grab the proper time zone and your recordings will continue to record at the incorrect time.