Yes. When you upgrade or downgrade a plan, the billing date will be restarted based on the time of this change.
Customers who are updating a plan from an active subscription will receive a proration discount, based on the unused portion of their previous plan.
Customers who purchased a lifetime plan will be eligible for a proration discount only if they update their plan within a week (7 days) from the time of purchase.
Please find the details with examples on Freemius’ page.