Probably not that many devices, at a guess. We've already had one GPS week number rollover and most GPS hardware now handles it by assuming the current date is

Probably not that many devices, at a guess. We've already had one GPS week number rollover and most GPS hardware now handles it by assuming the current date is after the firmware was released (so they'll mostly break 19 and a bit years after the last firmware release, not on the rollover). Oh, and this also means that some devices have had rollover-related issues before the actual rollover date. Some of the early, out-of-support Trimble devices apparently haven't been able to get the right date since 2016 for example.