The birth order of two twins has been reversed thanks to a strange twist in time.
When Emily and Seth Peterson welcomed twin boys, Samuel first and then Ronan a few minutes later, they were surprised to find that on paper, Ronan is actually older.
Giving birth on November 6 in Massachusetts, Samuel was born 5 pounds, 13 ounces at 1:39 a.m – just before day light savings kicked in at 2 a.m.
So, when Ronan was born 31 minutes later, the clocks had gone back one hour, and instead of it being 2.10 a.m. it was actually 1.10 a.m.
Speaking to ABC News, mum Emily Peterson, 32, said, "My husband was the first to say it, 'Here's a riddle for you!'"
"It literally took me a day to wrap my head around it. I didn't realise it was quite that big of a deal until my nurse turned around and said 'I've been working here 40 years and haven't seen anything like that.'"
A hospital representative said that because Ronan was born after the clocks had changed, legally they had to give the actual time of birth, which was before his 'older' twin brother.
"I personally think it's kind of cool that one's 'older' and one's born first," Peterson said. "Hopefully they're not going to be fighting over it for the rest of their lives."