Why Leap Year Adds Another Day to February

If you’re planning on taking GMAT this year, you may notice one extra day in your February study schedule. That’s right, 2016 is a leap year, but chances are you don’t know why February 29 comes along every four years or so.

 The history of leap year

 The reason 2016 comprises 366 days instead of the usual 365 is because the modern Gregorian calendar, which is the most widely used calendar in the world, needs to stay in sync with the Earth’s revolution around the sun, which takes 365.2 days—also known as a tropical Year. The Gregorian calendar has only 365 days, making it a quarter of a day short of the full tropical year.

 That’s where leap year rules comes in.

 The Julian and Gregorian calendars

You can thank Julius Caesar for first instituting leap years almost 2,000 years ago. What most of us don’t know, however, is that there are sets of criteria used to determine whether a given year should be designated a leap year. The Julian Calendar was not the most accurate in this regard.

 In fact, the Julian system led to a great deal of confusing by producing too many leap years, since the only criteria was that the year had to be divisible by four. Thus, in 1582 the Gregorian calendar was introduced, bringing with it a new set of rules for determining leap years.

 So, how are leap years determined in the Gregorian calendar? According to Discover, they must follow these rules:

• If the year is divisible by 4, then it’s a leap year, UNLESS

• it’s also divisible by 100, then it’s not a leap year, UNLESS FURTHER

• the year is divisible by 400, then it is a leap year.

 

If we didn’t add leap years, our calendars would be slightly out of sync with the Earth’s revolution. Still, the Gregorian calendar isn’t perfect, and no calendar used around the world reflects the exactly how long a year is on Earth.

 Making up the difference

 While the Gregorian calendar was a major improvement, it isn’t the most accurate calendar out there. The Revised Julian calendar is about ten times more accurate, for example, and it entails far more complex rules for determining a leap year: 

• Years that are evenly divisible by 4 are leap years, UNLESS

• they are evenly divisible by 100 and the remainder is neither 200 nor 600 when divided by 900.

So, why don’t we use the more accurate calendar? For now, the difference isn’t noticeable enough. The Gregorian calendar will be in sync until the year 2800, so there’s still some time to figure things out.

Depending on how your year has been going so far, this leap year could mean knocking out a few more items on your February GMAT prep to-do list. Or, if you’re looking to take a break from GMAT studying and have some fun on your extra day, you might curl up with a good romantic comedy—we suggest the movie Leap Year.

 Make this YOUR leap year, and use the extra day this February wisely to start planning your future. Get $229* off live GMAT prep courses today!

 

*Offer: $229 off applies to comprehensive In Person, Live Online, and Private Tutoring new enrollments from February 25, 2016 through February 29, 2016 11:59 p.m. PT only. Self-Paced, Math Foundations, Data Sufficiency, and Quiz Bank are excluded from this offer. Discount may not be combined with any other promotion or offer.

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