As I understand it, Armed Forces Radio in Europe no longer uses the six "pips' (like BBC) going up to the hour, but they did more than just alert you that it was top of the hour. I believe they also were used to make sure all network clocks were in-sync. Clocks that were just a tiny bit off would stop just before the top of the hour and follow the five pips and then the longer top of the hour pip would give the command and everyone was in-sync again, at least for the next hour or so.