With a six-minute lead, Harrison Egan rushed into the world at 12.22am at Calvary John James Hospital, after a short but relatively easy labor for Goulburn parents Lauren and Jackson Egan.

Midwives across the ACT rang each other to compare, and cheers rang out in the private hospital maternity ward. Their baby had won!

Evie Walsh came a close second, arriving at the Centenary Women and Children's Hospital at 12.28am and weighing 3.32 kilograms.

Harrison is the third child for the Egans.

"We were just hopeful for a very happy and healthy baby but I think everyone's very excited for a little boy," Ms Egan said.

The mother-of-three knew the sex but it was a happy surprise for her husband.

"It was very difficult to keep it to myself, but that was Jack's wish, he wanted to have a surprise," she said.

Older sister Olivia, 7, said her "intuition was right" when she found out about her younger brother.

"I've already got a sister, I don't need another one," Olivia told her parents.

Harrison was due on Janaury 9 but wanted to make a splash, having his first ever photoshoot at only 12 hours old.

Having a New Year's Day birthday would be an "excellent" party, especially when Harry turns 21, Mrs Egan said.

"[I hope] there's no fighting between siblings, he grows up strong and happy and healthy, and knows he's loved," she said.

Baby Evie's parents Jessica and Daniel Walsh were also just happy to have a healthy baby, even if it was on New Year's Day.

They are going to be pretty broke every December and January from now on, Mrs Walsh joked.

Their oldest daughter, two-year-old Mia, was born December 21, so the two siblings will bookend Christmas.

Evie was born at 38 weeks.

Mrs Walsh was glad Evie made it into 2024, even if earlier than hoped.

"The doctor last night said, 'You might have one of the first one ACT', and I was like, 'No, that's only three hours away, we're not ready for that'," she laughed.

There was a "countdown towards midnight", Mr Walsh said.

"All the nurses are very happy and excited, which was very nice, it was a very good experience."

Despite the early and unexpected arrival, the couple were very organised and had planned a quiet New Year's Eve just in case.

They had bags packed in the car and even had grandparents on standby to care for Mia.

They will have to get used to having quiet end-of-year celebrations, Mr Walsh joked.

"We can't get too hungover on New Year's Eve because we'll be wrapping all the presents of the birthday the next day," he said.

Mrs Walsh said she was distracted caring for her eldest, so by the time she arrived at hospital Evie was well on her way.

Both babies were content and sleepy on Monday morning.

In addition to being the first babies of 2024, they share a fairly unique birthday.

New Year's Day is the third least common birthday in Australia, following leap day, February 29, and Christmas Day.

Regardless of the practicalities of having a New Year's Day birthday, Harrison and Evie have a lot to look forward to.

Babies born on January 1 are supposed to carry good luck with them throughout their lives, especially if born at midnight.

No wonder they both rushed into the world nice and early.