In the 90s a friend of mine made a watch that just showed the year. The year precisely, that is to say, considering leap seconds. This is much harder than it s

In the 90s a friend of mine made a watch that just showed the year. The year precisely, that is to say, considering leap seconds. This is much harder than it sounds because the protocol used (DCF) transmits the leap year info spread out over a time span before the year change. So suddenly your stupid receiver + display needs memory and compute.