LEAP SECOND TIME ADJUSTMENT DAY – December 31
Sun Dec 31st

Leap Second Time Adjustment Day

Leap Second Time Adjustment Day is listed as a commemoration only. Scientists who have been around for many years do not make changes. But, if they do, it's either June 30 or December 31.

The majority of the world's time is based on a 24-hour day in which each hour contains 60 minutes, and each minute contains 60 seconds. The measurement is much too simple for accurate time measurement.

Scientists have attempted to convert the hours of the day into a standardized and precise way of measuring since about 140 AD. The 24 hour day measurement is not an exact science due to the Earth's rotation's constant variability. The validity of leap second adjustments is being questioned by some. Scientists who have been around for many years do not make changes. But, if they do, it's either June 30 or December 31. Scientists have gained 27 leap seconds between 1972 and 2020. The fact that the Earth's rotation is slowing is another factor that is affecting the atomic clock, which means the length of our day is getting longer. Scientists found that no leap second was required in 2020.

How to celebrate #leapsecondtimeadjustmentday on the second day of the adjustment period

Here are ways to celebrate: whether an adjustment is made or not.

  • Quantum Leap's episode is a preview
  • Play the game leapfrog
  • Bruce Springsteen's "Leap of Faith" is a podcast
  • Sneak up on someone and see if you can get them to leap into the air
  • Leap for joy
  • Watch the moon landing and listen for Neil Armstrong's famous quote
  • Sing the 12 Days of Christmas and see if you remember which day leaps
  • Take a leap of faith

To post on social media, use the hashtag #LeapSecondTimeAdjustmentDay.

History is on record of a leap second time change day

In 1972, scientists first introduced the leap-second device.