If you can figure out some way to upload it to your desired destination and get a link to it, maybe this bot can help you post on lemmy at a specific time of the week/day.

I recently found jtx board.
It has journal, todo list, and notes functions but it can be customized to only show whichever function you use on the main screen.

Be the change you want to see in the world. I’ll sub to it.

Large Text: Banner Creator

It’s not foss (i know that kinda defeats the purpose) but it needs no account, no permissions and has no ads.