With the same person? As long as they are up for it sure. And as long as they are not the first and second date.
With different people? As long as your dates know you are dating them exclusively, yes.
Is going on two dates on one day acceptable?
If it's with the same person, it is. If it's two different people, it's not.
I would say no lol
Yes, as long as what motivates you is the companionship and communion rather then the conquest.