I would change it more often, I really would, but I'm too lazy to do it via mysql command line and the backend page I've been using to do it for years has become a total, roaring pile of shit.
It timed out, and I'm not joking when I say this, 14 times in doing the update; which when you consider I'd copied & pasted all the text into the buffer and was just pasting and clicking OK ...
Anyway, I'll attempt to do it slightly more often. I won't bother doing it every week perhaps but I didn't want it to cross the actual year mark