In my experience it is as wldtrvlr stated.

When membership is close to expiring every WC you go to they attempt to get you to renew. I have always done it at my home WC (sfo) so that the angels working there can receive the "credit." It has been explained to me that the "credit" also can determine the hours of operation or even whether or not the wc stays open. I hope you take the hint and renew at sfo