After discovering that the most recent event began at 18:00 (not 17:00, as advertised at the FreeBSD home page), I took a closer look at the .toml file entries for the two series. …
Context: https://www.freebsd.org/events/#past (captured 2022-12-15).
Origin of diff 1 here: https://github.com/freebsd/freebsd-doc/pull/105.diff.