just an anecdote about UTC vs GPS time. GPS time doesn't have leap seconds.
So my team was testing a system with some devices, one of which was a GPS and the main system had UTC from NTP. We had a big display that showed all our data including both times, so we could monitor what was going on. So the two displayed times were 13 seconds apart (the number of leap seconds then). Our program manager was a smart guy but gaffe prone. So in a demonstration of our system he blurted out to the whole room of observers, 'hey something is wrong, those two times are different'. We cringed and explained, but it sounded like we were covering up an error. But he would go on to repeat the gaffe again to a different group.
So my team was testing a system with some devices, one of which was a GPS and the main system had UTC from NTP. We had a big display that showed all our data including both times, so we could monitor what was going on. So the two displayed times were 13 seconds apart (the number of leap seconds then). Our program manager was a smart guy but gaffe prone. So in a demonstration of our system he blurted out to the whole room of observers, 'hey something is wrong, those two times are different'. We cringed and explained, but it sounded like we were covering up an error. But he would go on to repeat the gaffe again to a different group.