How to determine leap year

According to the Julian calendar, a yearin which February has 29, and the number of days is equal to 366, called a leap year. Every fourth year to the usual 28 days of February added another day. However, this algorithm for calculating a leap yearand after the adoption of the Gregorian calendar in 1582 , the yearhave to be changed.

Instruction

1. Divide the numeric value of the yearand 4. Those yearand that will not be a multiple of 4, do not apply to leap year.
   Example.
   2008 year / 4 = 502
   2011 year / 4 = 502,75
   2008 year is a leap year (evenly divided), according to the rule of step 1, 2011 is not a leap year (divisible with remainder).
2. After successful completion of step 1, divide the numeric value of the yearand on 100.
   If the year is divisible by 100 without remainder, this year will not be a leap year, even if it was successfully divided into 4.
   Example.
   2104 year / 4 = 526
   2104 / 100 = 21,04
   2104 year is a multiple of 4 but not multiple of 100 (when the division turned out the rest).
   According to the rule of step 2, it is a leap year. 2100 year / 4 = 525
   2100 / 100 = 21
   2100 a year is a multiple of 4 but a multiple of 100. According to the rule of step 2, it is not a leap year.
   But here too there may be exceptions. For more accurate calculation, follow step 3.
3. Need year, the numerical value which was a multiple of 4, and 100 divided by 400. If it divided without a remainder, then the year, after all, a leap!
   Example.
   2100 year / 4 = 525
   2100 / 100 = 21
   2100 / 400 = 5.25 in
   2100 year not divisible by 400, then, according to all the rules, he's not високосный2000 year / 4 = 500
   2000 / 100 = 20
   2000 / 400 = 5
   2000 year evenly divisible by 4, 100, but at 400. Consequently, according to the rule of step 3, it is a leap.