Well, from my understanding, the write-up by the security company posted in the sub-tweet explain that it's not only the current date, it's just a weak algorithm that only uses the current date as seed, and only that.
And this mechanism is complementary to regular auth, so admin password was _something_ but the bypass allowed you (if you reverse engineered the algorithm) to login without knowing it.
So that's still a firmware issue indeed for me, no admin set voluntarly its password to current date.
The write-up in question: https://claroty.com/team82/research/freeze-the-controller-de...