Here’s the answer…
Little Samuel Peterson was born at 1.39am on Sunday, November 6.
He was followed 31 minutes later by his twin sibling Ronan, at what would have been 2.10am.
However, at 2am that morning, the clocks went back an hour, meaning Ronan was actually born at 1.10am, according to the official record, making him older on paper than Samuel.
The clocks went back a week later in the US than in the UK, where it happened on the last Sunday in October.
The brainteaser was posted to Facebook in November by Cape Cod Healthcare, along with a photo of the boys with mum Emily and dad Seth, from Massachusetts, US.
Adam Thurmond wrote: “Congrats to giving birth to time travellers”, while Alyson Lucey joked: “They are going to fight forever about who is older.”
Deb Totten, a maternity nurse at the Cape Cod Hospital where the twins were born, said: “It’s the first time I have ever seen this in over 40 years of nursing.”
Realising how close his sons were going to be born to midnight, Seth, 45, a trooper with the Massachusetts State Police, admitted he had a feeling there might be something unusual about it.
He 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.”
Stay-at-home mum Emily, 32, said during Ronan’s birth 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!”
Samuel and Ronan have since joined their big sister Aubrey, two, at home.