Why do Leap Years usually happen every four years?
During a Leap Year, one extra day is added to the Gregorian calendar, meaning that there are 366 days in the year in total.
The calendar dictates there are usually 365 days annually, as this is the approximate time it takes for our planet to orbit the Sun.
However, the time it actually takes for the Earth to orbit the Sun – to be exact – is closer to 365.25 days.
Therefore, in order to ensure the calendar remain synchronised with the solar seasons, an additional day is marked on the calendar every four years.
According to Daniel Brown, associate professor in the School of Science and Technology at Nottingham Trent University, if we didn’t observe Leap Years, then in around 750 years’ time, the coldest time of the year would fall in June.
source: express.co.uk