(KRON) – A twin brother and sister were born in 2021 and 2022, respectively, just 15 minutes apart, at the Natividad Medical Center in Salinas, California.

Parents Fatima Madrigal and Robert Trujillo welcomed a baby boy named Alfredo Antonio on New Year’s Eve at 11:45 p.m. Fifteen minutes later, his little sister Aylin Yolanda entered the world at midnight on Jan. 1, 2022.

“It’s crazy to me that they are twins and have different birthdays,” said Madrigal in a press release announcing the rare birth. “I was surprised and happy that she arrived at midnight.”

Aylin weighed 5 pounds, 14 ounces, and Alfredo weighed 6 pounds, 1 ounce.

What are the odds of a birth like this? Some estimate the chance of twins being born in different years is 1 in 2 million, the press release said.

Dr. Ana Abril Arias, who helped deliver the twins, said the birth was one of the most memorable deliveries of her career.

The fraternal twins have three older siblings who are very excited to meet them, Madrigal said.