Dear All, The voting pattern has swung away from 1.5s to 0.5s and we shall see whether this trend continues!
There is an embellishment to Mike Shaw's comment: The radio clock stopped for 1 second at midnight This isn't quite what happens. Indeed, there seems not to be a general pattern. The Definitive UTC Clock is more a mathematical construct than a physical object that ticks along with high precision. It (the construct) certainly never stops and, during the night, it ticked up: 23:59:59 23:59:60 00:00:00 The formal representation of UTC midnight is 00:00:00 and one second before that (in this special case) is 23:59:60. There is a continuum of times in between, like 23:59:60.875 There are real clocks which can and do display 23:59:60 but I don't own one. The U.K. six-pip time signal extends to seven pips and I have heard that. The U.K. telephone-service speaking clock gets it right too but only by a fudge. You hear: At the thiiiiiiiiiiird stroke... with a bit of noise in "third"! Ordinary domestic radio-controlled clocks adjust themselves at some convenient time later. None of mine had changed at 00:30 but all had by changed by 07:00. Given my special requirement, I checked a radio-controlled clock against the speaking clock before I set out. You can't trust radios these days. Most are digital and give the six (or seven) pip signal about 2.5s late. The speaking clock is really two clocks which normally run in sync. One is live and the other is back-up. When the clocks go forward or back an hour, the two are set exactly an hour apart and someone throws a switch at the critical moment. You don't hear any stutter in the spoken words. When the clocks go back one second the same thing happens. Someone switches from one clock to the other but in the middle of the word "third". Remember, the speaking clock announces times which are multiples of 5 seconds. It announces 23:59:55 and then lets the next announcement start running before the switch is thrown. The speaking clock never announces 23:59:60. I am a huge fan of leap seconds and see no reason to change this scheme until the earth starts slowing down more than 2 seconds a year. All this wind power and tidal power could accelerate that happening! Frank --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
