Imogen Stockwell is a Christmas baby, sharing her December 25 birthday with the likes of actor Sissy Spacek and Canadian Prime Minister Justin Trudeau.
The museum curator celebrated with a cricket match with extended family on a sandbank exposed by low tide in the middle of Otago Harbour.
''Normally, I don't celebrate my birthday on my birthday,'' Ms Stockwell said.
''But today, I'm making people celebrate it a bit more.
''I decided, if you don't do it when you're 30, I'm probably never going to do it.''
As to the experience of having a birthday on Christmas Day, she said that was all she knew.
''To me it's just pretty standard. This is the first year I've actually had my birthday dinner on my actual birthday.''
As child, she used to have her birthday on August 25.
That date was half-way between her sister's birthday and her father's birthday.
It was ''nice'' to have a birthday celebration on her birthday, but she was not sure whether she would do it again.
''I guess only time will tell.''
