Names of the days of the week the "first day". This convention is also found in some Austronesian languages whose speakers were converted to Christianity by European missionaries. In Slavic languages, some of the names correspond to numerals after Sunday: compare Russian "vtornik" "Tuesday" and "vtoroj" "the following", "chetverg" "Thursday" and "chetvertyj" "the fourth", "pyatnitsa" "Friday" and "pyatyj" "the fifth"; see also the Notes. In Standard Chinese, the week is referred to as the cycle of the stars (). The modern Chinese names for the days of the week are based on a simple numerical sequence. The word for "week" (which is literally translated to "star day")
IAU (1976) System of Astronomical Constants and in 1979 and 1980 by a theory of nutation . There were no reliable rotation elements for most planets, but a joint working group on Cartographic Coordinates and Rotational Elements was installed to compile recommended values The IAU(1976) system is based on the astronomical system of units: IAU commission 4: , IAU (1976) System of Astronomical Constants The International Astronomical Union at its XVIth General Assembly in Grenoble in 1976, accepted (Resolution No. 1 a whole new consistent set of astronomical constants recommended for reduction of astronomical observations, and for computation of ephemerides. It superseded the IAU's previous recommendations