To me it looks like it is counting members' posts from the last 24 hours, rather than from a set time. Getting it to count could be a bit tricky because of the time changes that go on bi-annually here; it might have to be set to a GMT time reference or something. I'm not sure if I'll actually be able to get it to recount that list at a certain time (i.e. there might be other board statistics tasks linked in with that process) but I'll have a look.

Alex