They were actually changing every 3 weeks for the last few months so they "should" be changed tomorrow. Although there were a few exceptions. The previous batch actually changed after 2 weeks and once (I think it was December) it took 4 weeks. But the majority of changes have been happening on every 3rd Saturday, so my bet is on tomorrow.
Edit: Correction, they're changing them today, one day early, either cause of the OP or cause it's the 1st of the month. The ones that close don't reopen, so new ones are coming.