1. Daily entries in The Astronomical Almanac of various quantities that assist in calculating the apparent places of stars from their mean places given in catalogues. The quantities tabulated include nutation, the obliquity of the ecliptic, and Besselian day numbers. Second-order day numbers are used in high-precision calculations, particularly for stars at high declinations.

2. The Julian Day Number, which is the whole-number part of the Julian Date.