Julian Day functions, version 1.1, for Russ Webb's RPN calculator.
By Marvin E. Wilborne III, copyright (c) 1997 Marvin E. Wilborne III.

Overview
========

This function set allows you to add and subtract dates and times to compute
future or past days and times using Russ Webb's RPN calculator.

If you don't have Russ Webb's RPN, you will need to install it before
installing these functions.  It is available from his web site at:

        http://kale.ee.cornell.edu/pilot/

        This calculator is shareware and requires a seperate registration
        sent to Russ Webb.

Detailed Function Explanation
=============================

Function        Result
-------------   ------------------------------------------------------------
jd              Julian Day
                
                compute the Julian Day number of the date on the stack.
                date format should be:  MM.DDYYYY, or for May 7, 1958, you
                would use 5.071958

                This function works for all dates including and after
                15 October 1582.

mjd             Modified Julian Day

                compute the Modified Julian Day number, also known as the
                number of days since November 17, 1858 which is used in 
                orbital elements for artificial satellites.

dd              Delta Days

                Compute the difference in days between two dates on the stack.
                For example, if you enter 1.011963 and then 7.171997 and press
                this function, you'll get an answer of 12616 days.

d#              Day of Week

                Compute the day of the week for the number on the stack.  For
                example, 9.111997 (September 11, 1997) returns 4 which is
                Thursday.  0 is Sunday, 1 is Monday, ..., 6 is Saturday.

tdy             Today

                Put today's date on the stack, in mm.ddyyyy form.

y2k             Year 2000

                Put Jan 1, 2000 date on the stack, in mm.ddyyyy form.

!               Ouch!
                Compute the number of days until Jan 1, 2000.

                Ouch! is what you'll hear when programmers look at this
                countdown and see how few days are left before the year
                2000 and their software breaks.  This set of functions
                is Year 2000 compliant.  (You can only use 4 digit years.
                It is not year 10000 compliant!)

dec             HMS to Decimal

                Convert a time on the stack in hh.mmss format to decimal hours.

                This function is useful for adding and subtracting times.
                For example, to add 3hrs 45mins to 2hrs 13 minutes, use these
                steps:

                "3.45"  Press "dec"     3.75
                "2.13"  Press "dec"     2.216667
                "+"                     5.966667
                Press "hms"             5.5760   (which is 5.58,rounding error)
                                        (I'm going to see what I can do...)

hms             Decimal hours to HMS

                Convert a time on the stack in decimal hours format to hh.mmss

jdt             Julian Day and Time

                Take a date date in second position on the stack, in mm.ddyyyy
                format, and a time in hh.mmss format on the top of the stack 
                and convert it to a Julian Day and Time number.

mdy             Monday Day Year

                Take a Julian Day number on the stack and return the
                corresponding Monday, Day and Year in mm.ddyyyy format.

                For example, the Julian Day value of 245144.5 returns the mdy
                value of 1.012000 (or Jan 1, 2000).

                If you want to know what date is 3000 days from today, you
                would use these steps:

                Press "tdy"     9.111997        ; the value for this example
                Press "jd"      2450702.5       ; the equivalent Julian Day
                "3000 +"        2453702.5       ; add 3000
                Press "mdy"     11.282005       ; November 28, 2005
                Press "d#"      1               ; it's a Monday

now             Now

                Put the current time on the stack.

mdyt            Take a Julian Day and Time number and convert it to mm.ddyyyy
                and hh.mmss in stack position 2 and on the top of the stack
                respectively.


Release Notes
=============
22 Sept 1997    Bug fix in "jdt"-it didn't test correctly for enough
                parameters on the stack.

                added drag and drop functionality to all functions that only\
                require 1 parameter.

12 Sept 1997    Initial release.


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

Address comments or questions by e-mail to:

        wilborne@gamewood.net

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.
