Calc on the fly??

I am trying to create a reminder system. I would like all the reminders to be in a separate table so I can generate reports (i.e find all reminders due next week).

The reminders have different start dates, and different lengths so for example

Reminder A = StartDate1 - 1 months

Reminder B = StartDate1 – 1 week

Reminder C = StartDate2 – 3 months

There will also be "custom" reminders where they can add their own date and description.

Etc.

I have 3 tables

Data (this is the table that is the "main" data – "StartDate" is in this table)

RemindersType (the table that holds all the various Types of reminders i.e SerialID, ReminderName, ReminderLength

RemindersData (creation of reminders in here that ultimately display in a portal in Data).

This is a renewal reminder kind of system so once the renewal has been activated, the same set of reminders need to be re-generated.

My question is this:

There is no way to automate these reminders is there? I.e the user will have to click on a button – generate reminders.

Is there a way to do a calculation on the fly? I mean at the moment this is how I see the script:

Set $$DataID; DataID

GoTo RemindersData

Create New Record

Set DataID $$DataID

Set TypeID "1"

And this is where I get stuck, where do I do the calc of the date? It needs to identify the Type to beable to do the calc, then the end result of this needs to go into "due date" in the reminders data table. I believe I read somewhere that Variables will not do date calculations.

Sorry if I'm not clear. TIA