This post is followup to a series.
He also pointed out an available placeholder that I didn't notice: %shelf_expire_time%. This uses a library setting that you can configure in the client to determine your available hold expiration dates automatically. This is better than adding the date manually, and was either added sometime after I originally changed our receipts in 2008 or I just didn't know about it since I hadn't looked through most of the library settings at the time. Perhaps someone will find another use for mod-DateAdd, but it's not necessary for hold expiration dates.