2016's jump year was watched on the last Monday, this February. Google has celebrated the 29 February by giving the date that only comes around once every four years its own - DOODLE.
Due to planetary orbits, the season that 2016 has an additional day, however, the earth's orbit takes 365.24 days to complete its solar orbit and an extra day every four years is added to keep calendar seasons consolidate with solar seasons.
February was chosen as the month to have the leap day as it is the only month without 30 or 31 days.
According to the theory, the second month of the year had 30 days before the reign of Roman Emperor Augustus. Augustus supposedly wanted his month, as August, to have as many days as July, the 31-day month named after Julius Caesar. As the theory goes, August was then only 29 days long, he took two off February for the benefit of August. In reality, there is evidence that the direct predecessor of the Gregorian calendar, the Julian Calendar marked February with 28 days before August became a 31-day month. The "additional" day of Feb. 29 was added to the Gregorian timetable in 1582 to represent the Earth's turn around the sun of 365 days and 6 hours.
In the UK, the legal date of birth is considered on non-leap-years as March 1, if someone is born on February 29.