The issue with a calendar is there is a need for someone to maintain the same; we would need five mods in this Forum to do that. 
However, if there is a member who wishes to maintain a calendar, it's likely we can arrange an early post for that. We will also look into establishing a calendar similar to the inflight meetup linked to above.
Met
FlyMeToTheLooneyBin yesterday at the LAX FL, and at Gate 43,
anabolism sharing the F cabin on AA136 (delayed over an hour by someone iirc in J who may have had an allergic reaction - and with three checked bags distributed in three luggage bins, you can imagine...)