Prorate a product

Hi Community,

Has anyone found a work around for prorating a product purchase?

We have a product that is available for a year (Jan. 1 2018-Dec 31, 2018) and people pay one price for that. If someone purchases after March 1st and anytime until say October 31 we want to set up a prorated price that calculates automatically. Has anyone done anything similar successfully?

Thanks for any feedback.

Cathy