There’s nothing unusual about a set of twins being born at different times—or even different days, depending on when delivery begins. But what about different years? Now that is a birth story for the history books.

California twins Alfredo and Aylin Trujillo have two completely different birthdays in two completely different years. Alfredo was born on New Year’s Eve, 2021, at 11:45 p.m., and his sister Aylin arrived 15 minutes later (at the stroke of midnight, no less) on New Year’s Day, 2022 at Natividad Medical Center.

“Natividad is excited to announce we welcomed Monterey County’s first baby of 2022!” the hospital wrote in a Facebook post. “Greenfield twins Aylin and Alfredo Trujillo were born just 15 minutes apart, but what makes their birth so rare is that they were born on different days, months and years.”

Both twins are healthy and happy, which is the most important thing. The second most important thing is how their mom and dad will plan their birthday parties every year (Jointly? Separate parties? The possibilities are endless!).

“It’s crazy to me that they are twins and have different birthdays,” proud mama Fatima Madrigal said. “I was surprised and happy that she arrived at midnight.”

According to the Centers for Disease Control and Prevention, there are approximately 120,000 twin births annually in the United States—these births make up just over 3 percent of all births.  But twins with different birthdays are rare. The odds of twins being born in different years is one in two million, according to The Book of Odds.