The wheel turns eight times a year. Be here on the day itself, scan, and the sabbat's stamp and its card are yours. Miss one and the wheel simply comes around again.
Balance again, and the gathering in.
Mabon rests on the autumn equinox, the second harvest, when day and night stand equal before the dark half of the year. It is the witches thanksgiving, a time of gratitude, preserving, and letting go of what will not keep.
Common practices
Four visits, four stars. Collect four stars and earn a free small drink with purchase.
Or just keep scanning. The card always turns over, signed in or not.