# Is 2017 a leap year?

# 2017 is not a leap year, it is a common year.

## February 29th, 2017 is not a valid date.

The last leap year before 2017: 2016.

The next leap year after 2017: 2020.

Details below.

## The leap year algorithm. The three conditions to check in order to know whether a year is a leap or a common one:

### 1) A leap year can be evenly divided by 4:

#### 2017 is not evenly divided by 4.

### 2) Except if it can be evenly divided by 100 then it isn't a leap year:

#### 2017 is not evenly divided by 100.

### 3) Except if it can be evenly divided by 400, then it's a leap year:

#### 2017 is not evenly divided by 400.

## 2017 is not a leap year, it is a common year.

What is a leap year?

#### A leap year has 366 days.

2017, being a common year, has 365.

#### In a leap year month February has 29 days.

February 29th is a valid date.

In a common year month February has 28 days.

February 29th, 2017 does not exist.

### How often do the leap years occur?

#### Nearly once every four years is a leap year. More exactly, leap years occur 97 times in every cycle of 400 years.

### Why do we need leap years in our calendar?

#### Leap years keep the calendar year in sync with the astronomical year, preventing us, for example, from celebrating Christmas in the month of November.

## The last leap year before 2017: 2016.

The next leap year after 2017: 2020.

## Is it a leap year? Last leap year before & next leap year after this year

### The leap year algorithm. The three conditions to check in order to know whether a year is a leap or a common one:

#### 1) A leap year can be evenly divided by 4

#### 2) Except if it can be evenly divided by 100 then it isn't a leap year

#### 3) Except if it can be evenly divided by 400, then it's a leap year

## Latest checked up years / leap or common years?