THESE three girls could be called dated, but not in the usual sense.
Right on schedule, little Holly O'Shea arrived into the world at the weekend, much to the delight of her parents.
Granted, she was a week late if you go on the medical advice given to her proud mum and dad.
But she was precisely on time if you go on her recent family history -- because she now shares a birthday with her two older sisters, Georgia (4) and Anna (2).
And along with all being born on January 2, the girls were born exactly two years apart, in 2007, 2009 and 2011.
Parents Mike and Stella O'Shea will have little excuse if they ever forget a birthday.
"It certainly wasn't planned. You couldn't have planned it," Stella told the Irish Independent yesterday.
"They were all natural births and they were all late. It was just the way it worked out that I ended up getting pregnant in March and giving birth in January."
The family, from Milltown, Co Kerry, have conducted research online and so far have not been able to track any other family with such perfect symmetry.
Although Holly was due on St Stephen's Day, the little girl took her time, arriving instead on her sisters' birthday.
Four-year-old Georgia had kept her parents waiting for 11 days and two-year-old Anna was eight days overdue.
"I can't believe Holly was born on January 2 as well, but I was glad she hadn't arrived when she was due -- the weather was so bad," she said.
"We're absolutely delighted with her though and that everything went well and we have three healthy little girls.
"At least I'll never have to worry about seasons where clothes are concerned and poor Holly will have all the hand-me-downs."
And there must surely be economies of scale savings to be had on future birthday costs?
The girls' father, Mike, said his two older daughters were over the moon with the new arrival, although they're still too young to understand the significance of the date.
They'll doubtless be expecting another sister in 2013.
"They know Holly was born on their birthday and they're very excited about the new baby and just can't leave her alone," he said.
"We're delighted to show them off. It's nice to have a bit of good news for a change.
"We've been trying to get in touch with the Guinness Book of Records, but we've had no joy yet on that.
"We started out by enquiring with the local paper if this had ever happened before and Stella did some research on the internet."
Stella said that curiosity got the better of her and she logged on to Google in an attempt to find out if her family was truly unique, birthday-wise.
"I found a family in America where two boys and a girl shared a birthday and we found another family with three boys, but there was no record of any family with girls with the exact same time-space between them," she said.
This year on their birthday, an aunt made a fuss of the two older girls while mum and dad were occupied at Kerry General Hospital.
Next year, it will be mayhem with three cakes to ensure each girl remembers it's her special day -- even though it is shared with her sisters.
And the family can look forward to hosting three separate 18th birthday bashes -- and three separate 21sts -- on January 2 within eight years from 2025.
Lecturer in midwifery at University College Cork, Rhona O'Connell, said there was no medical explanation why a woman would give birth to her children on the same date.
"It's a chance occurrence unless the mother had been induced but other than that there's no maternity reason why that would occur," Ms O'Connell said.
A statistics professor at Ohio State university concluded that the odds of a family having three children born on the same day in different years were about eight-in-a-million.