# Count the number of days of a specific month using NumPy

• Last Updated : 02 Dec, 2020

In order to count the number of days of a specific month, we will be using numpy.datetime64() method of numpy module.

Examples:

```Input: month = 2; year = 2016
Output: 29 days

Input: month = 12; year = 2020
Output: 31 days```

Let us assume the month whose number of days we want to count be P and the next month is N. We will subtract the first date of the month P from the first date of the month N. Implementing this in numpy.datetime64() method.

Syntax:

For all months except December:

`numpy.datetime64('yyyy-N-01') - numpy.datetime64(yyyy-P-01')`

For December:

`numpy.datetime64('yyyy-P-31') - numpy.datetime64(yyyy-P-01') + 1`

#### Below are various examples which depict how to count the number of days of a specific month using numpy module:

Example #1:

In this example, we will find the number of days in the month of February of the year 2016.

## Python3

 `# import module``import` `numpy`` ` ` ` `# explicit function to calculate``# number of days``def` `calcDays(month, year):``    ``date ``=` `0`` ` `    ``# December case``    ``if` `month ``=``=` `12``:``        ``end ``=` `str``(year)``+``'-'``+``str``(month)``+``'-31'``        ``begin ``=` `str``(year)``+``'-'``+``str``(month)``+``'-01'``        ``date ``=` `1``    ``else``:`` ` `        ``# single digit months``        ``if` `month < ``10``:``            ``endM ``=` `'-0'``+``str``(month``+``1``)``            ``beginM ``=` `'-0'``+``str``(month)`` ` `        ``# double digit months``        ``else``:``            ``endM ``=` `'-'``+``str``(month``+``1``)``            ``beginM ``=` `'-'``+``str``(month)`` ` `        ``end ``=` `str``(year)``+``endM``+``'-01'``        ``begin ``=` `str``(year)``+``beginM``+``'-01'`` ` `    ``# return number of days``    ``return` `(numpy.datetime64(end) ``-` `numpy.datetime64(begin)``+``date)`` ` ` ` `# Driver Code`` ` `# get month``month ``=` `2`` ` `# get year``year ``=` `2016`` ` `# call the function``print``(calcDays(month, year))`

Output:

`29 days`

Example #2:

Here, we will find the number of days in the month of April of the year 2001.

## Python3

 `# import module``import` `numpy`` ` ` ` `# explicit function to calculate``# number of days``def` `calcDays(month, year):``    ``date ``=` `0`` ` `    ``# December case``    ``if` `month ``=``=` `12``:``        ``end ``=` `str``(year)``+``'-'``+``str``(month)``+``'-31'``        ``begin ``=` `str``(year)``+``'-'``+``str``(month)``+``'-01'``        ``date ``=` `1``    ``else``:`` ` `        ``# single digit months``        ``if` `month < ``10``:``            ``endM ``=` `'-0'``+``str``(month``+``1``)``            ``beginM ``=` `'-0'``+``str``(month)`` ` `        ``# double digit months``        ``else``:``            ``endM ``=` `'-'``+``str``(month``+``1``)``            ``beginM ``=` `'-'``+``str``(month)`` ` `        ``end ``=` `str``(year)``+``endM``+``'-01'``        ``begin ``=` `str``(year)``+``beginM``+``'-01'`` ` `    ``# return number of days``    ``return` `(numpy.datetime64(end) ``-` `numpy.datetime64(begin)``+``date)`` ` ` ` `# Driver Code`` ` `# get month``month ``=` `4`` ` `# get year``year ``=` `2001`` ` `# call the function``print``(calcDays(month, year))`

Output:

`30 days`

Example #3:

In the below program, we will find the number of days in the month of December of the year 2021.

## Python3

 `# import module``import` `numpy`` ` ` ` `# explicit function to calculate``# number of days``def` `calcDays(month, year):``    ``date ``=` `0`` ` `    ``# December case``    ``if` `month ``=``=` `12``:``        ``end ``=` `str``(year)``+``'-'``+``str``(month)``+``'-31'``        ``begin ``=` `str``(year)``+``'-'``+``str``(month)``+``'-01'``        ``date ``=` `1``    ``else``:`` ` `        ``# single digit months``        ``if` `month < ``10``:``            ``endM ``=` `'-0'``+``str``(month``+``1``)``            ``beginM ``=` `'-0'``+``str``(month)`` ` `        ``# double digit months``        ``else``:``            ``endM ``=` `'-'``+``str``(month``+``1``)``            ``beginM ``=` `'-'``+``str``(month)`` ` `        ``end ``=` `str``(year)``+``endM``+``'-01'``        ``begin ``=` `str``(year)``+``beginM``+``'-01'`` ` `    ``# return number of days``    ``return` `(numpy.datetime64(end) ``-` `numpy.datetime64(begin)``+``date)`` ` ` ` `# Driver Code`` ` `# get month``month ``=` `12`` ` `# get year``year ``=` `2021`` ` `# call the function``print``(calcDays(month, year))`

Output:

`31 days`

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