Suzy is celebrating her eighth birthday today but in one way, she is just two years old!
That's because she was born on 29 February during a leap year.
February normally has 28 days. But every four years, in what's known as a leap year, it has an extra one - the 29th.
So even though Suzy has been alive for 8 years, she has only been able to celebrate on her actual birthday twice - making her 'two'!
People born on the 29th of February are called leaplings.