Failing the broadcast date being available presumably the source files(s) will have a creation/modified date that could be used as a decent proxy. Some streaming services I use often have the date one day later than then event but that would suffice for the use case I gave.
Ah, yes! I see the progress bar on my mobile for an extended highlights I watched yesterday. I will have to remember to cast BT TV from my phone all the time rather than use the Youview box app. In any case the mobile app seems to get any new content appreciably sooner that the Youview box app. Another approach would be to make a note of the weekend's matches in my copy of the Radio Times and tick them off as I go (annoying that there is not web site I can find that lists recent and upcoming fixtures without sticking the result on those games already played).