One of the actual cesium beam atomic clock units used in the 1960’s “flying clocks” experiment the synchronise time around the world. And later in the Hafele–Keating experiment to prove relativity theory. Currently kept at Agilent (formally Hewlett Packard) Melbourne headquarters. It’s accurate down to the nanosecond, but they still put an analog display on the thing. Image credit: Binarysequence/Wikimedia
Once again, it’s the time of year when, for reasons that surpass understanding, we set our clocks back one hour. Once again, I’m writing to remind you, and me, to set all the bloody clocks back.
Yes, strictly speaking, we set the clocks back now because we set them forward in spring, but I think you get the idea.