Where are the rest of the 3 days are going if the earth is revolving around its own axis in 23 hours 56 minutes 4 seconds?

Question

Earth revolves around its own axis in approximately 23 hours 56 minutes 4 seconds. If we measure the length of a day by 24 hours we hour saving 180+56=234 seconds a day. In a year that is 234 * 365 = 85, 410 seconds. In 4 years that is 341,640 seconds. Now a say has 86400 seconds, so we are the end of 4 year we have 341,640/86400 = 3.95 days. But we add 1 day to February after 4 years. Why is this?

In: 2

Answer 1

The earth is actually rotating a little bit faster than it is revolving around the sun, so each day on Earth is actually slightly shorter than 24 hours. This means that the extra 3 minutes and 56 seconds of rotation are added up over the course of a year and, by the end of the year, the days have added up to 3 days. So, the 3 days are simply the extra time it takes for the earth to complete one full rotation around its own axis.