MoonFN, version 1.1 for Russ Webb's RPN (Shareware)
and MoonFN, version 1.1 REGISTERED Version
Copyright (c) 1997 by Marvin E. Wilborne III

Overview
--------

This function set extension to Russ Webb's RPN calculator (seperately
available shareware from http://kale.ee.cornell.edu/pilot/) computes
several Moon values for a user selected date and time:  The age in days,
the %illumination, and the phase.

Operation
---------

It's important that your RPN calculator be in Degrees mode.  I will add a
conversion in the near future that will handle the calculator being in Radian
mode.

The answers that have dates and times in them are returned in UT, unless you
set a value in UTC which is the offset for your area or time zone.
For Danville VA that is currently -5.00 on 11-13-1997.

To compute the age of the moon in days, for today at local midnight time,
press "T" and then press "AGE".  To compute the age of the moon in days for
one to 5 days in the future, press "X" select the number of days, and then
press "AGE".

To compute the age of the moon in days, for now, press "N" and then press
"AGE".

Once you select a date and time, all other calculations are based on the
value set.

So, if you press "%I", you'll get the percentage of illumination for the date
and time previously selected.

Press "?Ph" to get the phase, reported as "New moon", "Waxing Crescent",
"First Quarter", "Waxing Gibbous", "Full Moon", "Waning Gibbous", "Last
Quarter", or "Waning Crescent".

You can manually set a date by entering it in YYYYMMDD.HHMMSS format on the
stack and press "D".

This program differs in how dates and times are entered compared to other
function sets I've written.  Specifically, I've changed to a format that
allows you to enter dates and times as a single value on the stack for
improved efficiency and easy display.  The other function sets will probably
be upgraded to this format in the future-for consistency between function
sets.

Button Definitions
==================
UTC     - set the UTC offset, enter it as decimal hours from UT, i.e. -5.00

T       - set the date for calculations to today at midnight
X       - set the date for calculations to one to five days from today at
          midnight
D       - set the date to the value on the stack in YYYYMMDD.HHMMSS format.
N       - set the date and time to NOW.

Age     - based on the date set using T, X, D, or N, calculate the age of the
          moon in days.
%I      - based on the previously set date, calculate the percentage of
          illumination of the moon.
?Ph     - Calculate the phase of the moon and return the answer using the
          standard english phrases.

?V      - Check the current value of the Date being used for calculations,
          or the value of UTC (Offset from Universal Time in decimal hours),
          or the current UT (Universal Time) value (answer in YYYYMMDD.HHMMSS
          format).
?       - Display the registration and version information.

Registration
============

This function set is Shareware.  You can download it and use it for 30 days
without registering.  If you continue to use it after 30 days, please
register by sending $5.00 to:

        Marvin E. Wilborne III
        124 Matthew Circle
        Danville, VA 24540

Or you can register on-line at PilotGear's Shopping Mall:
        http://www2.viaweb.com/pilotgearsw/marwiliii.html

Or you can call PilotGear at 800-741-9070.

If you've already registered a RPN function set that I've developed, then
you're already registered for these.  I call it cross registering.

Address comments or questions by e-mail to:

        wilborne@gamewood.net


Release Notes
-------------
14 November 1997        Update 1.1.  Changed completely the method used to
                        calculate the age and phase of the moon so that it
                        is more accurate (the previous version was only
                        accurate to within a day), and so that the answers
                        are more closely aligned with the values provided by
                        U.S. Naval Observatory.

                        Removed the ?Next function until a more accurate
                        method of calculating the values can be developed.

13 November 1997        Release version 1.0 of both the shareware, time
                        limited version, and registered full function version.

Legal Notice
============
This software is copyrighted (c) 1997 by Marvin E. Wilborne III. Furthermore,
I make  no warranty with respect to the quality of this software, nor do I
warrant that its operation will be error-free. The author claims no liability
for data loss or any other problems caused directly or indirectly by use of
this application.

This function set may be freely distributed provided that this file is
included with the PDB file that contains the functions.
