This is an important date for the 2-in-5 criteria for capital gains exemption.

However, nothing has worked out to date for better or worse.

Each room will have a separate lease on it with a separate deposit following normal property management practices, and like you said, the leases have different start dates. 

But yes, now that we are here, maybe let him know that if things do not get up to date or cleaned up you will go to his superiors.When people are late right at the beginning, I let them know that the behavior is not acceptable and let them know there are consequences to that bad behavior. 

Most softwares will list (at least) name of guest, stay dates, ADR, and revenue to owner.

Sure you can get away with it , until a home inspector looks at the dates on electric wire , or pvc pipe . 

I take a picture of their driver's license.I ask for phone numbers that accept texts and any alternate land or business phone numbers.I ask for the names and birth dates of anyone under 18, and ask if there are any service / emotional support animals, together with their names and breeds.I also ask for personal references, previous landlord contact info (and length of time there), employer contact info (and how long there, together with earnings), as well as the name and contact information for their manager / boss.

Give them notice that their lease will end and you expect them out by a specific date/time.

To record it as December, you would have to back date it and the bank reconcilation would be off.

Keep track of every property--the address, purchase price/date, sale price/date, profit, rent at purchase, rent at sale, cost to renovate, take before and after pictures.