Help with formula

I currently am trying to figure out how to write a formula to count what wasn't completed during a certain date range. IE 10/1/2018 through 10/31/18. I have two columns i need to compare, Plan and Actual. So if a cell in the plan column has a date withing October but the actual column it relates to has no date this it will count it. I hope i am explaining this better this time, please let me know if you need anything clarified. Attached is a sample of the worksheet i am working on. It is extensive to say the least.

Thanks!