Plugin Guide - Between Month Days

This discount requirement can be used with any other discount type.

To use this discount rule, the discount requirement type should be configured as Discount between month days and need to provide values for Start day & End day between which you want this discount rule to be applied as displayed in the image below. The Start day should be less than the End day. 

Once saved, the discount requirement will be added to the discount as displayed in the image below.

That's all you need to do in order to use this discount requirement in your nopCommerce store.