In Brazil, approximately 110 individuals from the state of Mato Grosso who were born on February 29 experience an unusual situation: they officially celebrate their birthdays only every four years during leap years. This peculiarity raises questions, especially in years like 2026 when there is no February 29, creating ambiguity around how to handle birthday celebrations and age counting for those born on this date.

According to Brazilian law, individuals born on February 29 cannot be registered on an alternative date, a change from previous practices. The regulation mandates that February 29 must appear on their official documents, confirmed through the Declaration of Live Birth (DNV), which is issued by the hospital and signed by the attending physician at the time of birth. This official protocol ensures that their actual birth date is recognized legally, although it has historically led to challenges, as recounted by many families.

One notable story is shared by Teresa de Figueiredo, a 70-year-old retired teacher, whose father faced significant difficulties while trying to register her birth date on February 29. Despite the obstacles presented by the registry office, her father insisted on using the correct date due to the emotional significance tied to it, illustrating the deeper implications and societal challenges faced by leap year babies. This quirky predicament continues to generate curiosity and discussions about identity and aging for those celebrating their birthdays every four years.