Sorry to drag this up again, but I've kept an eye on Jonas1102's player
Yorick Bittle, and it appears he has the same issue that Zeustis' players had -- in the playoffs he had 13 days of ML Service Time, and yet now in their off-season, he has 25 days of ML Service Time. Bittle was added to the 40 man roster on 10/22 at 1:42 PM, and promoted to the Majors on 10/28 at 3:10 PM, which works out to 18 days on the 40 man roster BEFORE his call-up. So I still don't understand how he has 25 days, instead of either 13 or 31. But it at least seems it is reproducible.