NAME

Date::JD - conversion between flavours of Julian Date

DESCRIPTION

For date and time calculations it is convenient to represent dates by
a simple linear count of days, rather than in a particular calendar.
This is such a good idea that it has been invented several times.
If there were a single such linear count then it would be the obvious
data interchange format between calendar modules.  With several
versions, calendar modules can use such sensible data formats and still
have interoperability problems.  This module tackles that problem,
by performing conversions between different flavours of day count.
These day count systems are generically known as "Julian Dates", after
the most venerable of them.

Among Julian Date systems there are also some non-trivial differences
of concept.  There are systems that count only complete days, and
those that count fractional days also.  There are some that are fixed
to Universal Time (time on the prime meridian), and others that are
interpreted according to a timezone.  Some consider the day to start at
noon and others at midnight, which is semantically significant for the
complete-day counts.  The functions of this module appropriately handle
the semantics of all the non-trivial conversions.

The day count systems supported by this module are Julian Date, Reduced
Julian Date, Modified Julian Date, Dublin Julian Date, Truncated Julian
Date, Chronological Julian Date, Rata Die, and Lilian Date, each in both
integral and fractional forms.

INSTALLATION

	perl Build.PL
	./Build
	./Build test
	./Build install

AUTHOR

Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

Copyright (C) 2006, 2007, 2009, 2010, 2011
Andrew Main (Zefram) <zefram@fysh.org>

LICENSE

This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
