The next leap year is: 2020
That’s right! Did you know that almost every 100 years a leap year is skipped? In fact 3 out of 4 centuries skip one which means that sometimes it can take up to 8 years instead of 4! For example, the last leap year of the 21st century will be the year 2096. The year 2100 will be skipped and we’ll have to wait for 2104 to be the next.
In this article we cover all the reasons for these exceptions. We’ll explain what a leap year is, when they will be occurring, why some of them are missing and how to easily calculate yourself.
Don’t Want To Read The Whole Article?
Here’s our video that explains it all in a couple of minutes. It’s very easy to understand with helpful illustrations. If you prefer to continue reading please be our guest, we cover everything further down below.
What Is A Leap Year?
We guess most of you already know that a calendar year contains 365 days. These days are divided amongst 12 months of which the most have either 30 or 31 days. However February only has 28. Anyways, all together they add up to the number 365.
So what defines a year?
A year is the time it takes the earth to finish it’s cycle around the sun. In other words, it’s the amount of time our planet travels around this giant ball of fire until it returns to it’s starting point.
Now let’s do some simple calculations:
A day contains 24 hours, so multiplied by 365 that equals 8760 hours a year right?
Let’s say we would grab a stopwatch and take a seat in a very comfortable chair. We’d press “go” and wait for earth to travel around the sun until we are back in the exact same spot. We’d press “stop” and realize that it took 8765 hours, 48 minutes and 46 seconds.
In other words it takes us longer to finish our cycle than our calendar actually says. After 4 years we’ve almost slowed down by a whole day! That’s why we need to compensate in order to keep our calendars on track. Every 4 years the month of February therefore gets an additional day which makes it 29 in stead of 28. Everything seems fine again.
But hey, it’s not exactly 6 hours a year…
You’re absolutely right! And this is where it gets interesting. Like we said before we “lose” 5 hours, 48 minutes and 46 seconds per year. So no, it’s not exactly 6 hours. And therefore after 4 years it’s not exactly 24 hours. If we do the math we can conclude that after 100 years we’ve “won” an additional day using the strategy above. So that’s 1 day too much!
Tell us about it! So after 100 years we got an “extra” day that we have to get rid of in order to keep our calendars synchronized with the universe. But how do we get rid of it? Well, this one is pretty simple. We just skip one of the leap years every 100 years. We do that whenever a date is precisely dividable by a hundred. This means that in the year 2100 we won’t have one, nor will we enjoy one in 2200 or 2300.
Is this precise in the long run?
Unfortunately not. If we live by these calculations (which we will keep aside for the sake of this article) we actually “lose” another day every 400 years. We can’t simply accept that because after 73.000 years we would have Christmas in the middle of summer. That’s why another rule was set into place: Every 400 years we skip the “100 year rule” and stick to the leap year. That’s why back in the year 2000 we actually had one. We’ll also have them in 2400, 2800, 3200 and so on.
Was that it?
Yes! If you made it this far you’re a champion. Nothing else you need to understand. This is it! Let’s just share a quick summery-image to live by.
In case you comprehend everything we’ve been saying there still is a very tiny deviation. Every 8000 years we would be off by one day. However for now that’s something we can live with. How the future will unfold remains a question mark. Maybe there will be exceptions that can not be solved by the 24 hour schedule we live by. Who knows every 8000 years a new rule will be applied. And after that we might have to do the same thing at a certain point in time. Just stick with the instructions we taught you and you’ll be fine for a lifetime.
Possible Changes To Leap Years
Depending on how long mankind will survive there’s one thing we’d like to mention. The exact length of a day isn’t exactly fixed. The 24 hours we all know actually has a deviation of 0.005 seconds which decreases over time. 100 years from now it’s very likely that our days will be shortened by 0.001 seconds. We won’t take out our calculator again but it’s going to take millions of years to even take this into consideration. Who knows if we’re all living on Mars by then!
So, How Often Is A Leap Year?
We guess you’re able to give the answer to that question yourself now. Not 4 years like we all have been told at a younger age. It’s way more complicated than that. On average it’s a little less but it’s safe to say that for the next 80 years this is the case. Good enough right?
In regards to astrology there’s a calendar shift happening as well. We won’t go into details at this point but it’s something worth mentioning. Horoscopes have shifted over time as the sky is not a fixed image. How will this all play out in the long run? We have an interesting article about astrology vs astronomy in case you’re interested. Our article on Ophiuchus also covers the Sidereal vs Tropical astrology approach in case that interests you. We hope you enjoyed our discussion and that you have learnt something from it!