% $Id$

\subsection{Implementation Notes}

The algorithm for computing between Gregorian dates and Julian days is given 
in Fliegel and Flandern ~\cite{Fli68}.

The algorithm for computing between Julian dates and Julian days is given 
in Hatcher ~\cite{Hat84}.

The {\tt Calendar} class defines two methods for converting in both
directions between the core {\tt BaseTime} class representation and a
calendar date.  Calculations of time intervals (deltas) between
time instants is done by the base class {\tt BaseTime} in the core units
of seconds and fractional seconds.  Thus,  a calendar is only needed for
converting core time to calendar time and vice versa.
