A Summer Without a Leap Second
- Jan 14, 2021
- Blog Post
While the month of June will hopefully reveal a world recovering from the COVID-19 pandemic, it will not grace us with an extra glorious second of summer. I think we really could have used that extra second this year, but alas, the fickle spin rate of our home planet is not cooperating. So make sure you savor every normal second of June a little more this year to make up for the second that shall not be. Though unlikely, maybe, just maybe, the Earth in its own desultory way will speed up a little and provide an ephemeral bonus at the end of 2021. In any case, I hope you amass 86,401 seconds worth of enjoyment from all of your normal-length days.
About Leap Seconds
The International Earth Rotation Service (IERS) announces twice per year whether a leap second will be introduced to the civil time scale (UTC). The purpose of leap seconds is maintain agreement (to within a second) between the atomically kept UTC time scale and UT1 time, which tracks solar time and is based on the rotation of the Earth. There are two conventional opportunities for leap second insertion each year: the last day of June and the last day December, at the end of the day. It is also theoretically possible for a second to be deleted if the Earth spin rate were to increase, but this has not happened (yet) in the history of leap seconds. Leap second announcements are made approximately six months before each conventional opportunity.