William Markowitz (February 8, 1907 – October 10, 1998) was an American astronomer known for his work on the standardization of time.
William Markowitz was born Melč in Austrian Silesia (now in the Czech Republic) on February 8, 1907.
[1] Markowitz obtained his doctorate from the University of Chicago in 1931 under the supervision of William Duncan MacMillan with a thesis on the statistics of binary stars.
He subsequently worked with Louis Essen in England to calibrate the newly developed atomic clocks in terms of the ephemeris second.
At the International Astronomical Union (IAU) meeting in Dublin in 1955, he had proposed the system of distinguishing between variants of Universal Time, as UT0 (UT as directly observed), UT1 (reduced to invariable meridian by correcting to remove effect of polar motion) and UT2 (further corrected to remove (extrapolated) seasonal variation in Earth rotation rate), a system which remains in some use today.