But at 2am, Daylight Savings ended for the year making it 1.10am according to the official record, meaning Ronan is older than his brother.
Cape Cod Healthcare posted about the event on facebook, and shared a photo of the boys with mum Emily and dad Seth, from West Barnstable, Massachusetts.
Realising how close his sons were going to be born to midnight, Seth, 45, told One Cape Health News: "I said, they're either going to be born on two different days, or the time change may come into play."
Emily, 32, said she heard the nurses talking before seeing the hands moving backwards on the clock in the birthing room.
She admitted: "I thought my brain was playing tricks on me!"
Deb Totten, a maternity nurse at the Cape Cod Hospital, said: "It's the first time I have ever seen this in over 40 years of nursing."