word play can make my day

Yesterday a customer returned an advent calendar because there was a speck of red ink printed on a white number.  We did not have any more for an exchange, so she spent at least an hour going through all the other choices of advent calendars to find the perfect one.  She looked so miserable and her task seemed so pointless.  "I hope she finds her sad advent calendar," I thought to myself.  Then I spent the rest of the afternoon chuckling about Sadvent calendars.