I run a SKS key server and watch my daily numbers to see how many keys get updated, etc. Being a numbers guy I wondered how many people, like me, update their GPG keys, I specifically update the expiration date and generate new encryption keys annually, at the beginning of the new year. Apparently I'm not alone:
|Time||New Keys||Updated Keys|
Specifically these keys were updated at 1700Z. I'm not sure I have the ability to see which keys were updated but I'd love to know how that happened.