This blog saw a bit of a hiatus; I'm back, I might post a little more often.
I had used custom-patches to the engine's code-base to get group-by-time functionality for constructing the side-bar, but while I offered the patches upstream, I lost the time to write tests too. Life at a start-up, my time disappeared again and various factors led me decide to not spend what little time I had on the static site generator's codebase.
Then upstream diverged and my patches wouldn't carry across. Then upstream got vaguely equivalent functionality, but not enough.
Nudged to look again today, I saw that upstream had sufficiently improved that I could sensibly reimplement the calendar sidebar with their grouping logic. While not as flexible as what I had offered, it does cover everything I needed, and has the distinct benefit of being available, tested and working.
So I rewrote that bit, regenerated the pages, saw things looked the same, modulo only that now the links could all be made https, and so committed and pushed.
In the meantime, the blog got HTTPS via the awesome Let's Encrypt and I'll probably look at tuning the server to force HTTPS-only.
I resolve to hereby stick to upstream code-features from now on.
-The Grumpy Troll