The rule
An e-commerce have a 20% off offer valid for entire month of July.
How to apply the technique
Using the Equivalence Partition technique we could divide this as
But we can do a little better with this case. We can use the boundaries of the partition to ensure we are covering the set as follows:
Using this specific inputs into our test cases design, we are going to ensure that the offer is valid inside July, and not outside it.