by Cynthia Germain

Leap years are like bonus days in our calendar. You know, the ones when February gets an extra day—February 29th. But why do we have leap years, and what do they mean for someone who is, say 80 years old?

Our Gregorian calendar works in 365-day cycles. However, the Earth takes about 365.25 days to orbit the sun. That extra quarter-day might not sound like a big deal, but over time, it adds up. So to keep our calendar in sync with Earth’s orbit, we have leap years. They happen every four years, giving us that extra day in February. But it’s not as simple as adding a day every four years.

Here’s how leap years work:
If a year is divisible by 4, it’s a leap year.
But if a year is divisible by 100, it’s not a leap year, except if it’s also divisible by 400.
These rules help us stay close to the real length of a year, which is about 365.25 days.

Leap years aren’t just about adding an extra day. They help us stay in tune with nature’s rhythms. For example, in Wisconsin, where farming is prominent, knowing when seasons start and end is crucial. Leap years help farmers plan better because they keep our calendar aligned with the changing seasons.
Imagine someone here in Door County who’s 80 years old. They’ve seen quite a few leap years in their lifetime. So, let’s count the leap years:

From 1944 to 2024, there are 20 leap years if we count every 4 years.
We must exclude the years divisible by 100. There are 7 such years: 1900, 2100, 2200, 2300, 2500, 2600, and 2700. Out of these, 2100, 2200, 2300, 2500 are not leap years because they are not divisible by 400. So these don’t count for our 80 year old.

So, for our octogenarians, they have in fact experienced 20 leap years!

Leap years aren’t just quirks in our calendar; they’re reminders of how we try to fit our human-made systems with nature’s cycles. In Wisconsin, where agriculture and the changing seasons matter, leap years play a part in how we plan our lives. For someone who’s 80 years old, those extra days are like little surprises in the flow of time, making life just a bit more interesting. So when February 29th rolls around this week, remember: it’s not just an extra day; it’s a reminder of our journey through time, especially in our home in Wisconsin where nature’s rhythms shape our lives.