List archives "Next" button new behavior

A few weeks ago, the "Next" button on pages like
https://www.postgresql.org/list/pgsql-www/since/202507100000 changed
behavior:

Old behavior: "Next" would use the timestamp of the newest message as of when
you last loaded the page. "Next" would take you to a page containing that
timestamp and all newer-timestamp messages. For example, as I'm writing this,
the newest message has timestamp 2025-07-10T14:03. "Next" used to take me to
https://www.postgresql.org/list/pgsql-www/since/202507101403 and I'd then see
the 14:03 message and later messages, if any.

New behavior: As long as the latest message is from 2025-07-10, "Next" takes
one to https://www.postgresql.org/list/pgsql-www/since/202507100000. Also,
visiting https://www.postgresql.org/list/pgsql-www/since/202507101403
redirects to 202507100000 (zeroing the HH:MM from the request).

(I'm simplifying; there are more behavior nuances if one starts at a date far
enough in the past for messages to fill the page.)

Does anyone have background on this change? I found no discussion of it.

I liked the old behavior better, since it made the "Next" button convenient to
see everything since I last caught up. That said, I'll adapt if the change is
intentional and/or favored.

Thanks,
nm