I guess you are referring to the "last updated" date on the data? I used to expire all data at 10 days, but last year I began to allow members to choose an expiration between 5 and 30 days, and those who don't expect to move soon often choose the longest possible. They get an e-mail one day prior to expiration.
The images themselves are rebuilt as I said, every night, whether they've moved or not.
