You can have a field(s) to sort on and display different fields.
Humans in the US prefer their dates formatted as month/day/year.
Humans in other parts of the world prefer their dates formatted as day/month/year.
Computers, in order to sort correctly or determine earlier or later, MUST have their dates as Year/month/day if you are going to format them.
So, if you are OK with older people born in May sorting before younger people born in January, use the birth date to sort. If all you want to do is sort by month and day, then use Format()
Select ...., Format(bDate, "mmdd") AS MySortDate, Format(bDate, "dd mm yyyy") As MyDisplayDate
From YourTable
Order by Format(bDate, "mmdd");