I think it's because they are service apts, maybe the rules are a bit different.
The rent at the current place is $45K/month so I was just calculating the extra day ($1500) being wasted at the old place, even though I won't be there on that last day.
The new place said they are like a hotel, you pay the day you "check in" so to speak. If that's the case, then the old place should be like a hotel too and let you leave before 10AM when you "check out" and not have to pay that day. But it doesn't work like that.
Oh well. I just wanted the rent to start on the first just for making it easy to remember, I realize rents don't have to be on the 1st, I was just trying to make it that way since I was starting a new lease. My current lease ends on the 21st I was trying to extend to to the end of the month.
Looks like it won't be on the first anyway because we have people from the U.S. coming that weekend, so we'll have to move a couple days before.