1 decade has 315,360,000 seconds.
That is, if we go by the typical per-year total, which is 31,536,000 seconds.
However, if we want to be more accurate, we have to take into leap years.
There are 2 or 3 leap years per decade. In the 2020s, for example, there are 3 leap years (2020, 2024, 2028). In the 2030, there will be only 2 (2032, 2036). And back to 3 leap years in the 2040s, and so on.
If it’s leap year, then 1 year has 31,622,400 seconds.
Seconds in a decade calculation
Two leap year decades
That means in decades with 2 leap years, we have the following math:
= 8 normal years (seconds) + 2 leap years (seconds)
= 8 * 31,536,000 + 2 * 31,622,400
We note that it’s close, but not exact, to our number mentioned at the top. (It’s 0.05% greater.)
Three leap year decades
In decades with 3 leap years, we have the following math:
= 7 normal years (seconds) + 3 leap years (seconds)
= 7 * 31,536,000 + 3 * 31,622,400
That’s 0.08% greater than the figure cited at the beginning of this article.
How do we know the number of seconds in a year?
But let’s also back up for a second because we simply told you the number of seconds in a year.
Let’s go through step-by-step how we got there:
– We know that 1 year has 365 days (366 days during leap year).
– We know that 1 day is 24 hours.
– 1 hour is 60 minutes.
– And we know that 1 minute is 60 seconds.
So if we multiply all that through, we have:
= 365 days per year x 24 hours per day x 60 minutes per hour x 60 seconds per minute
= 31,536,000 seconds per year
Of course, now that you know that there are 86,400 seconds per day, you can calculate how many seconds there are…
– per week
– per year (above)
– per century…
…and virtually every other expanse of time.