Hello. 👋

I forked the site and experimented a bit, I found the issue is in _includes/archive-single.html at line 42 when its formatting the year, it’s expecting a post.type and post.venue which aren’t in the .md files, causing only , , 2020 to be displayed, to just display the date you can replace the line with this:

<p> <time datetime="{{ post.date | default: "1900-01-01" | date_to_xmlschema }}">{{ post.date | default: "1900-01-01" | date: "%B %d, %Y" }}</time> </p>

Which is a piece taken from line 46 in the same file (_includes/archive-single.html) - displaying the month, day and year, or you could add the post.type and post.venue to the .md file meta.

I hope that helps you. 🙂