I then went to "past" and nothing from yesterday.
I then realised this site is based off the current front-page.
So I forced the "past" page to be today, and it's the third result: https://news.ycombinator.com/front?day=2026-03-16
But it's not on my actual front-page.
So this must have been done at a very brief window when this story was top, which even hnrankings didn't capture: https://hnrankings.info/47393619/
I think this would be better if powered by https://news.ycombinator.com/front , which is relatively stable after a day.
Otherwise you've ended up with a brief snapshot, and not the top posts of the day.
It also seems odd to have a "summary of 16/03" produced while that day has barely begun in the US timezone, so looking retrospectively at the previous day would make this better.