Here is a link of details: Define a condition check

Basically you create condition checks as required with a set of rules. You add a condition check reference field onto your form. The condition checker runs once per day and updates those fields according to the rules you've assigned. It will only set that condition once so if you have one set up to say "Expires in 15 days" then it won't set it again until it meets another condition (i.e. "Expired")

You can then set up email notifications to fire off based on that field being set to certain values. We use this to send the warning along with the value of that field so it is always correct (i.e. "Expires within 15 days" in the subject line.) When it is set to expired, you could have a business rule cancel everything.

1. Set up your condition check field on the table (type: reference, reference: Condition)

2. Set up your 1 or many condition check definitions for that table on your condition field. Note: their order should be last condition first and first condition last. So my expired condition is order 25, my expires within 15 days is order 50 and my expires within 30 days is order 100.)

3. Set up your events to fire.

4. Set up your email notifications triggered by your event, depending on what you'd like to be sent out.

5. Set up your business rule to cancel/reject if your expired condition is met.

My example of a condition check on a field I created on the user table to warn managers when a contractor's end date is approaching: