No, but you'd have to consider the time zone it was created in. For example, I was born in Chamorro Standard Time while I now live in Mountain Standard Time. So practically the place of my birth is a day ahead. You could say in Mountain, my birthday should be the 10th but in Chamorro it's the 11th. But for practicality everyone just considers the day's number as their b-day. It's accurate to a degree.
Yes it is, isn't it? I wonder if that means people are doing this birthday stuff wrongly then? What if it was not just one day per year? or never meant to be?