I participate in two groups, each of which uses different methods.
The Thursday night group plays weekly, in person, and I want people to approach it as much like a regular bowling league night as they can. Routine. If a player can't make it, we still play as long as we make quorum (half +1). We use a text message group to handle updates, changes, notifications of being late or unable to make it, etc. We've tried other methods since not everyone was capable of receiving texts at the time (yahoo group, MS Classroom), but now it's text messages and it's easy.
The alternate Saturday group started as a mid-pandemic online group and remains online. We use Discord to serve up our audio, Roll20 for the tabletop. For that one, we use Discord to pass on schedule changes.
There are a couple of monthly groups run by one of the players from the Thursday night group (I'm not in either group), where they have a useful method: the first thing they do when they meet for a game session is pull out their calendars and schedule the next session. So the schedule may not be super regular, but they always get the next one on the books.