DateTime::Astro implements functions used in astronomical calendars:
- Solar Longitude
- Solar Terms
- Lunar Longitude
- New Moons
... etc

This module is best used in environments where a C compiler and the MPFR
arbitrary precision math library is installed. It can fallback to using
Math::BigInt, but that would pretty much render it useless because of its speed
and loss of accuracy that may creep up while doing Perl to C struct conversions.

WWW: http://search.cpan.org/dist/DateTime-Astro/