Okay, so is this the ultimate time traveller's watch? Well, the battery can't die on you because there isn't one (solar power FTW) and while quartz timing packages and integrated circuits can and do fail, they're largely most vulnerable when there's a greater risk of moisture intrusion and this is a pretty well-sealed watch, so the humidity of a Cretaceous jungle shouldn't be a problem. It's highly impact resistant (obviously) and the sapphire and DLC coatings, plus the anodized aluminum, would give the watch an excellent chance, if a T. rex does chow down on you, of making it out the cloaca intact even if you don't, so maybe its fossil (embedded in a coprolite, no doubt) would be discovered in centuries to come, to clue your friends and fam into what happened to you.

The radio time sync would be of little use, but accuracy could be maintained by using the calendar and a homemade sundial to estimate mean solar noon and you could always re-set by that (accuracy would indeed eventually drift so far off as to be noticeable).