The rules are simple, as always:
1. Ride a century every month.
2. Post a report here. Pictures are always nice if you have them.
Just to answer a few questions that may come up:
(a) A century is one 100-mile (160.9 km) bike ride completed in one 24-hour day. Feel free to be more strict on how you define a century, but here we'll try to include as many people as possible.
(b) A century is not necessarily a group ride. It is simply a 100-mile ride which may or may not be done with a group and/or part of an organized event.
2021 thread:
2021 Century A Month Club