Using IF/AND statement for dates

Good day!

I hope someone can assist me with the following problem

I am trying to get a return value of Yes/No indicating if the customer is active for the current month based on the following (which are all dates)

Example 1
Contract Start Date: 01/01/2014
Contract End Date: *blank*
Current Month: 09/01/2019

In this case, the customer the customer is active for 9/2019.

Example 2
Contract Start Date: 03/01/2016
Contract End Date: 08/31/2019
Current Month: 09/01/2019

In this case, the customer the customer is NOT active for 9/2019.

Can someone please assist. I am really frustrated. Thanks