(Please excuse the username, I am not a PLEX administrator in any way.)
I created a simple program with python to fix this exact issue.
It takes an xml guide input file (-i), an xml guide output file (-o), and anything you want to exclude (-x) but will default to excluding ‘paid programming’, ‘pay-per-view’, ‘on demand’, ‘sign off’, ‘to be announced’, and “Shopping” if nothing is specified.
It adds an original-air-date record parsed from the actual air-date to the xml entries that are series (not movies) that do not adhere to the standard season-episode format nor already have an original-air-date entry.
I run this after running zap2it to get the xml tvguide, and then Plex picks up the resulting file. It works great for me. I can provide the source code if you need it.
example: TVGuideFix -i “c:\temp\PreGuide.xml” -o “c:\temp\TVGuide.xml” -x “Paid Programming” “RadiantTV Programming” “Pay-Per-View”
FixTVGuide.zip (7.0 MB)FixTVGuide_Source.zip (1.4 KB)