What's the Deal With a Leap Day?

One extra day of February is not what Portland’s looking for. So why do we do this leap year thing, again?

The simple version is that a trip around the sun takes planet Earth 365 days plus roughly a quarter of a day.

If we didn’t add the leap day every four years, the winter months would slowly become summer and vice versa. It’s all making sure the human-created system of time actually corresponds to the reality of the natural world.

Notable Trivia

Now here are some of the complexities:

• The leap day approach has been around since 45 B.C. thanks to Julius Caesar, who was creating a standard calendar for the Roman empire.
• But the author of the current system was Pope Gregory XIII. You may have heard it called the Gregorian calendar, for a reason.
• It actually takes the earth a few minutes less than 365 and a quarter days to revolve around the sun. The exact calculation, according to astronomers, is 365.242190 days. So leap years get skipped sometimes:
  • Leap days happen every four years except when the year is divisible by 100. But there is an exception to the exception: there is still a leap day when the year is divisible by 400. There was a leap day in the year 2000, but there won’t be 2100. (The Gregorian calendar introduced these complexities to keep the calendar in closer connection to the natural world.)
  • To deal with the same troublesome reality that one trip around the sun can’t be measured in a round number of days, other traditions opted for leap months. The Jewish, Chinese, and Buddhist calendars take that approach.

Leap Day Fun

For some, the extra day this year is a reason to celebrate.

• Get a special Voodoo’s Leapling doughnut. (Leapling, by the way, is the nickname for anyone with a Feb. 29 birthday.)
• Leaplings get free brownies at any McMenamins, which are also offering special cocktails and a find-the-(leap)-frogs scavenger hunt.
• There’s a party, appropriate for all ages, with arts and crafts at Ledding Library in Milwaukie at 3:30 p.m.