Every fourth year, the month of February has 29 days instead of 28. This year is called a "leap year" and the 29th day of February is a "leap day". A leap year has 366 days instead of the usual 365. Most years that can be cleanly divided by four are leap years. 2016, 2020 and 2024, for example, are leap years.
Vocabulary:
leap year = ano bissexto
leap day = dia bissexto
