Trick Question: How Many Seconds Are In A Year

Time is weird. Or, if you prefer, wibbly-wobbly^1^^.

Take someone who lives on a border between time zones and has a five minute commute. Separate clocks at home and the office show they make it in before waking up and that it takes two hours longer to trek home than it did to come in.


A more subtle strangeness is the Leap Second^2^^.

Like the days we add for Leap Years, these seconds keep our clocks and calendars from drifting away from their proper seasons. The expected math class answer for determining how many seconds there are in a year looks like this:

A year with a positive Leap Second is just slighly longer^3^^.

Notice the explicit use of "positive" above. That's required since Lead Seconds can, in theory, be negative.

Of course, Leap Seconds can happen on Leap Years too. So, based on our current system of time^4^^, a year can have one of six possible total seconds.

Leap Year Leap Second Number of Seconds
no negative 31,535,999
no –none– 31,536,000
no positive 31,536,001
yes negative 31,622,399
yes –none– 31,622,400
yes positive 31,622,401

Our global time keepers came up with the Leap Second in 1972. Since then, 25 have been added. All of the "positive" variety. And, we're ready for another one^5^^. This June will be one second longer than last.

Wibbly-wobbly indeed.