@matigo I’ve never tracked it, but suspect it’s more like monthly. I don’t have any science to it; I just decide it’s gotten a bit too long, and whack it back to trimmed and short again.
I think if I shave it rather than trim, it’s fine for a couple days, then pokey for a few days to a week, then comfortable again. There’s an intermediate length where it feels like it’s poking me whenever it brushes against something. Not shaving avoids that entirely.
The funny thing is that, before I stopped shaving, I got the tools and plenty of practice with double-edge razor shaving, so I can do a fine and pleasant job shaving if I want. But why burn the time every day or two?
Since I’ve stopped shaving, beards went from “sort of uncommon” to “absolutely everywhere” in my area, so I don’t even stand out for having one any more.