Lease Termination Date Discrepancy

[Phil LoCicero]

Good evening all. 
I have an odd question. I have some tenants on what we thought was a six month lease. I just noticed the lease states that it’s a six month stay but when we wrote it up the termination date is August first instead of the 31st. ( the 1st would make it five months)
I’m not overly concerned about it. If they left on the first it wouldn’t break my heart. If they stayed through all of August that would be fine too. 
My question is which of the numbers would be more likely to be binding in the eyes of the court? I realize what judge you get makes a difference as well.