Of course one can speculate that he could have been born a few days earlier.
But at this point, without hard evidence, what we have is speculation of what "might" have happened, against official documentation that claims what happened.
And even if hard evidence were to emerge that his mother gave birth to him in Kenya and then brought him back and filed for a US birth certificate, it would be plausible for him to maintain that he knew nothing about it until now, and always believed he was born in Hawaii.
I’m sure he’d say he knew nothing about it...except for the fact that he claims to have found his original birth certificate, the one with the footprint, in a book when he was a teenager.
No matter what else this proves, it shows irrefutably that Obama is a liar. He lies about anything and everything, probably even sometimes when he doesn’t need to do so. But then, we already knew that.