This is “The World Time Today” clock which is in Piccadilly Tube Station in London. It was installed sometime between 1925 and 1928 when the station was being renovated by the  architect Charles Holden and builders John Mowlem & Co. The clock features a time band which moves across its central line at the same pace as the earth rotates, and shows the rough time at any point at any time, and whether it is day or night. Few people notice the clock  in the station’s hustle and bustle as it’s one of London’s busiest.