How does a landlord calculate the amount that a holdover tenant owes?

Question Details:

My tenant was supposed to leave on the 15th of the month (lease ended then). However, even though a proper non-renewal notice was delivered to the tenant, they did not leave until late on the afternoon of the 17th. Regarding the holdover rent amount to ask for - is it only for 1day (the 16th) or can I ask the tenant for both days (16th and 17th)? At the end, I did not have the keys to the property until 6 pm on the 16th. Important Notice