These programs compute the geocentric and heliocentric distances and light-times to the major planets.   The distances to the planets are given in AUs (astronomical units) and millions or billions of kilometers or statute miles at 00h TD on each date of the given year and month on either the Julian or Gregorian calendar.   These computations are based on the VSOP87 theory.

SYMBOLS USED IN THE TABLES

AU = Astronomical Units

Mkm, Bkm = Millions, Billions of kilometres

Mmi, Bmi = Millions, Billions of statute miles

UT = Universal Time (UTC1)

TT = UT + ΔT (Terrestrial Time)
The barycentre is the centre of mass of the solar system.

ΔT = Time adjustment made to UT to obtain Dynamical Time (TD).
Due to its random nature, the exact value can only be determined by observation.   Generally, it changes at a slow rate and can be approximated, in some cases, based on observed trends.

NOTE:   For clarity:
1 million  =  1E+6  =  10⁶  =  1 000 000
1 billion  =  1E+9  =  10⁹  =  1 000 000 000