Determination of the day of the week *104804 + 4, "n" = 104804 and "k" = 4 which implies that August 13, 2009 is the fourth day into the 104805th week since 01/01/0001. 13 August 2009 is Thursday; therefore, the first day of the week must be Monday, and it is concluded that the first day 01/01/0001 of the calendar is "Monday". Based on this, the remainder of the ratio "Base/7", defined above as "k", decides what day of the week it is. If "k" = 0, it's Monday, "k" = 1, it's Tuesday, etc. Determination of the day of the week The determination of the 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 It superseded the IAU's previous recommendations