Leap Second Time Adjustment Day 2021 is on Wednesday, June 30, 2021: What is a leap year? Why isn’t a day 24 hours?


Wednesday, June 30, 2021 is Leap Second Time Adjustment Day 2021. What's In A Day?: National Tick Tock Day National Tick Tock Day

What is a leap year? Why isn’t a day 24 hours?

A day IS 24 hours, who told you different? There may be a second worth of adjustment now and then.

A leap year is to adjust for the fact that a year is not an even number of days, and is actually 365.24219 days. Read the reference for more details.


Shortest day?

Shortest day?

"There is no convienient arrangement to make a precise adjustment to our year every year so as they roll by the actual time of the of the Solstice actually becomes slightly early until adjustment of the leap year moves it back. The consequence of this is that a summer solstice on June 22 will gradually change to June 21 and earlier, a winter solstice from December 22 to December 21 and earlier."

looks like you are right

how many seconds in a century?

how many seconds in a century?

Seems deceptively easy. But remember to keep leap years in mind.

Every 4th year is a leap year. (I may be wrong, so make sure you check this out and make your own adjustments)

Therefore you will have 25 leap years in this case, with 367 days.

Regular years = 75 years

75 years * 365 = 27375 days

27375 * 24 = 657000 hours

657000 * 60 = 39420000 minutes

39420000 = 2365200000 seconds in regular years

Leap years = 25 years

25 * 366 = 9150 days

9150 * 24 = 219600 hours

220200 * 60 = 13176000 minutes

13212000 * 60 = 790560000 seconds in leap years.

Add them both up

3155760000 seconds in a century.

(Thanks Flossy for the correction!)

Note: You know what...to be honest, this depends when this "century" starts. It can include one more or one less leap year depending on when you start counting the years. This question is stupid and so is your teacher. But as long as you show that you've made your adjustment (which your teacher probably will look for) you should get 50 points.

Flossy: You're right. I made a stupid mistake. It's only 366 days.

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