Not a silly question at all, I was thinking about the same possibility. I don't know of a way to calibrate mine directly, but I could get a relative calibration by shooting a different gun that I'd chronied recently. Same pellets, same results, so I don't think the chrony is the problem. BTW, mine is a fairly new Beta Chrony.
Regarding "silly" questions, IMO, the only dumb question is the one you don't ask. So keep asking. Sometimes by not "knowing" something, you look at a problem in a new way. I know I learned more from the newbie electrical apprentices I had over the years than I did from most of the journeymen I'd worked for myself. Later.
Dave