Hi, Bert - most song circles meet on the same day of the month, month after month, year after year. In Sacramento, it's the second Friday of every month. It's on the first Friday of the month in nearby Auburn. For song circle to be successful, exceptions to the regular meeting dates should be rare.
I can't see how a calendar with exact dates would make things more clear. Or am I failing to understand what you're looking for?
-Joe Offer-