## Leap Year Calculator

### Hebrew Calendar Leap Years:

- During a Hebrew calendar leap year, an additional month of Adar is added.
- There are seven leap years in every 19 years.
- The 3rd, 6th, 8th, 11th, 14th, 17th, and 19th years of the 19-year Metonic cycle are leap years.
- 5777 is year number 1 of the cycle and is therefore not a leap year.
- The next leap year will be in 5779 -- year number 3 of the cycle.
- A mnemonic for remembering the years corresponding to leap years is: "גוחאדז"ט". The Hebrew letters Gimmel, Vav, Chet, Aleph, Dalet, Zayin, and Tet are used to represent the Hebrew numerals, 3, 6, 8, 1, 4, 7, 9.
- Mathematically, it can be determined if a year is a leap year by determining whether ((7*year)+1) mod 19) is less than 7.

### Gregorian Calendar Leap Years:

- During a Gregorian calendar leap year, an additional day is added to February.
- A Gregorian year is a leap year if it meets BOTH criteria:
- It is divisible by 4.
- It is not divisible by 100, unless it is also divisible by 400.

- 2017 is not divisible by 4, and is therefore not a leap year.
- The next leap year will be in 2020.