First, thanks for responding!
As for the url - that was a typo in my haste to post here. I have been linking it on other sites without the “www.” prefix, and, for example, using this exact url:
https://peta-file.com/scores/2016/2016_06_04__scores.txt
I receive a certificate error still on my home machine. Do you have any further suggestions?
I have a second computer at home, a macbook pro running El Capitan with Chrome 52.0.2743.116 it shows the certificate at the above posted URL to be valid. And, while I was posting I updated it to Chrome 53.0.2785.116 and it still shows the certificate to be valid.
Related to your second point, is it not a good idea to renew daily? I hate things ever getting close to their expiry but I suppose this is a bit excessive. I’ll change the cron job to run every 30 days, is that a better choice?