[MN] Surrendered property before lease was up, when should I legally receive my security deposit?

I moved out of my apartment on May 12th, handed over my keys and parking permit, and provided my landlord with my new address. I paid rent for all of May, despite moving out early, because my lease went until May 31st.

MN law states that the security deposit must be returned within 21 with an itemized statement for deductions, but does the 21 days start from when I surrendered the property (May 12th), or when my lease was up (May 31st)?

Thank you!