Most of our roughly monthly site upgrades come with seconds of downtime during which a maintenance banner briefly shows, so I don’t bother announcing them ahead of time.
However, in an upcoming update probably in the next week or so, I’ll be migrating the database to a new (faster!) version, and this is likely to take at least several minutes. I’ll take the opportunity to do some other site maintenance at the same time. Most of that time, the maintenance page will show.
Since running this site is a hobby, not a job, I’m not going to set a time for the migration and hold myself to it, but I’ll try to do it at a time when there aren’t a lot of people using it. The AI scraping robots that are constantly loading down the site will just have to suffer. 