Some questions on caledar algebra. (or I've got a shareware engineeeeeeee)

[Andre Garzia]

As my knowledge of Revolution grows I decided two things:

* All my lib stacks will be public domain with source so other (more 
serious) developers may benefit and improve my work.
* Some of my apps will be shareware so I can buy Rev documentation (I 
long for that).

Talking about my second topic, I decided to grow a little shareware 
engine. I made a stack called "Register & Preferences", this is a 
generic lib for handling preference data and app registration. I plan 
to make it as plug & play as possible. Currently it's very handy. You 
just attach it to you standalone and send command "SoapShareware 
<daystorun>" it will handle everything, check if it's the first run, 
register a preference file with the day it was instaled in a machine 
and also the days to run info. If the preference file already exists, 
it will read it and return it's contents by a callback handler.

Now comes the trick part, how to calculate if the shareware has 
expired. Is there a function to add days to a date and receive new 
date? Will I have to convert it to seconds and calculate? What you 
folks out there think it's wise to do...

PS: This stack & XML-RPC Stack will soon be available at my homepage 
(just let me parse that damm xml)

Cheers
Andre Alves Garzia  2003  BRAZIL
http://www.soapdog.org