Secret of eternal youth lies in your birth date

By LEANNE MOORE

In the youth-obsessed world of fashion, Denise L'Estrange Corbet can honestly say she will be 11 tomorrow.

The Auckland fashion designer belongs to a rather exclusive collection of individuals known as leap-day babies.

In her 44 years, L'Estrange-Corbet has celebrated her birthday just 10 times, tomorrow will be her eleventh.

Unlike most of us her birth date, February 29, does not appear on the calendar every year. She has to wait four years for February 29 to come around again.

"It's a really weird position to be in. Some friends forget my birthday when there is no February 29," says L'Estrange-Corbet, who produces the World label with her husband, Francis Hooper.

On average, only one baby in every 1461 is born on February 29, according to Statistics New Zealand.

So if you were born on February 29 and live in Coromandel township (population approximately 1460), there is unlikely to be anyone else living in the town who was born on the same day of the year.

In comparison, those born on any other day of the year could expect to find four others celebrating the same birth date.

L'Estrange-Corbet has only ever met one other person who shares her birthday, Auckland artist Julian Dashper.

Not only do they share the same rare birth date, they were born in the same year, in the same hospital.

The pair discovered seven years ago that their mothers had been in beds next to each other in the maternity ward at National Women's Hospital in 1960.

Tomorrow, 159 New Zealand children born on February 29, 2000, will celebrate their first true birthday when they turn four. A further 172 8-year-olds will celebrate their second birthday.

In total, about 2800 New Zealanders will celebrate their birthday on February 29, 2004 - not a good day for those businesses basing their trade on birthday celebrations.

On any other day of the year, more than 11,000 New Zealanders celebrate a birthday, says Bill Boddington, senior demographer at Statistics New Zealand.

On the years that the calendar skips her birth date, L'Estrange-Corbet celebrates on March 1.

But it always seems a fake birthday, she says.

"I try and do something really special on the proper ones."

The most memorable, she says, was her 40th (or 10th accurately speaking), when Hooper and their daughter Pebbles took her to Paris, and then New York.

"We stayed in a haunted 18th-century hotel near Notre Dame and in New York we went ice skating outside the Rockefeller Centre."

LEAP YEARS

* Leap years are needed so the calendar corresponds with Earth's motion around the sun, allowing the calendar to follow the seasons much more accurately.

* In the Gregorian calendar, which is the calendar used by most modern countries, leap years are divisible by four. But every year divisible by 100 is not a leap year unless it is also divisible by 400.

* In the Julian calendar, which was used before the Gregorian calendar was adopted, there was only one rule: Every year divisible by four was a leap year.

* The average year in a Gregorian calendar is 365.2425 days.

* The average year in a Julian calendar is 365.25 days.

* The Gregorian calendar was first adopted in Italy, Poland, Portugal and Spain in 1582. Great Britain and the United States introduced it much later, in 1752.