I was casually ruminating about day and month names today, partly because Japanese is so boring in that regard (although I have a list of antique Japanese month names somewhere, usually they just number the months). And I recall reading somewhere that Tolkien did a large part of his extra writing to establish stories (lore) to support his place names and languages.
I think if we name days and months at all, they might ought to receive proper names that reflect some aspect of tp culture. As opposed to word concatenations. Like (and I don't suggest this, just as an example) whatever day of the week jan Sonja first published a post on the language could be Founder's day (suno Ponta?)
Obviously years of work to do on that idea, some days might be named after events that haven't happened yet.