Positions of sun, moon and planets up to Pluto are calculated with an accuracy of the order of one arc minute for dates less than a century away from now. Calculations are based on approximation formulae by Paul Schlyter, which are in turn based on a preprint of a paper by T. van Flandern and K. Pulkkinen "Low precision formulae for planetary positions", Astrophysical Journal Supplement Series, 1980.

Information is retrieved about locations and time zones on earth, based on UNIX time zone data. The data contains information for over 350 locations world-wide and is even useful for dates centuries before UNIX machines existed. The same information is provided for about 2000 additional locations which have been assigned to UNIX time zone locations.

Currently, astrolib is implemented as a shared library for Palm OS 2.0 or later. It requires the MathLib library. Because the time zone data has been compressed quite a bit and the calculations do not require any external ephemeris data files, the library is only about 100K.

The astrolib source code is distributed under the GNU Lesser General Public License. As I understand the license, this means essentially that you can use astrolib from commercial and non-commercial software, but that you cannot make a commercial product out of a modified version of astrolib. Redistribution under the GNU LGPL is, of course, possible.

Click here to view the documentation online or to download the source.

Update Description:
New Features in Version 1.03:
- 2000 additional locations, each assigned to a timezone location
- Faster and flashable (pointer to global data is now stored in A4 register, no longer in own resources)
- Quick access to all locations in a country.