Skincare Product Rotation

Hello!
I have a question about the rotation of various skincare products.
I use both the Perricone Vit C Ester Restorative Cream and the MD Forte
Facial Cream with Glycolic Acid at night (not at the same time). My skin
benefits in a different way from each product.
Do you think it is better to alternate nights using the products, or to
rotate them on a weekly(or longer) basis?
Thanks!
Jeanne