June 30th to Have 61 Seconds In Last Minute?
How many seconds in a day? This can be answered easily by anyone who has a little knowledge. It is 86,400 seconds. But 30th june will have 86,401 seconds. How is it possible? NASA provided the answer for this question.
Due to the slowing down of earth’s rotation around its own axis, the last second has been added to 30th june to compensate it. This additional second is termed as a ‘leap second’. Generally, the last second of a day is 23:59:59, after which the next day starts at 00:00:00. But on june 30th, the last second of the day will be 23:59:60, after which the next day would start at 00:00:00. This means that we have to add an extra second to our watches to sync with the time change that occurs due to the leap second. It applies only to the Universal Co-ordinated Timing (UTS – automatic time) that is used by people all over the world. The time is so accurate that there could be a difference of only one second difference in 14,00,000 years.
The average length of a mean solar day is calculated based on the time taken for one earth rotation, which is about 86.400.002 seconds. NASA has realized that the rotational speed of earth is slightly slowing down due to forces caused by gravitational attraction between the earth, the moon and sun. A difference of two milliseconds was noticed per day. It was hardly considered at first but as time passed by, when the time lag is calculated per year, taking 2 millisec lag per day, the added up to 1 second. The International Earth Rotation Service keeps on monitoring this and adds a leap second whenever necessary. That is the reason aleap second is added either on 30th june or on 31st December.