February is a tricky month for genealogy research. Usually there are only 28 days in February, but every four years, 29 days occur in leap years like 2016 and 2020.
Leap years are needed to keep our modern day Gregorian calendar in alignment with the Earth's revolutions around the sun. It takes the Earth approximately 365 days, 5 hours, 48 minutes, and 45 seconds to circle once around the Sun. This is called a tropical year, and is measured from the March equinox.
However, the Gregorian calendar has only 365 days in a year, so if we didn't add a leap day on February 29 nearly every four years, we would lose almost six hours off our calendar every year. After only 100 years, our calendar would be off by around 24 days!
https://www.timeanddate.com/date/leapyear.html
February 29 events:
1792 – Italian composer Rossini was born.
1836 – John Henry August Beckman, a farmer of the O.B. Flat district of South Australia was born.
1932 - William Glasscock, a breeder of merino sheep at Greendale station, died at Gundagai aged 85.
1964 – Australian swimmer Dawn Fraser set a new world record in the 100m freestyle.