How to get last day of a month from date in PHP ?

Given a date and the task is to print the last day of the month. We will use date() and strtotime() function to get the last day of the month.

Used PHP functions:

• date() function: Format a local time/date.
• strtotime() function: Parse about any English textual datetime description into a Unix timestamp.

Examples:

Input: 2020-04-23
Output: Thursday

Input: '2018-09-11'
Output: Sunday

Approach:

• Given a date stored in a variable as a string, the step is to convert it into date format using strtotime() function.
• Once we get the date, we will employ date() method. Syntax:

  date( $format, $timestamp )

• Within $format, we will pass "Y-m-t" and within $timestamp the date taken above. In terms of date "Y" gives a full numeric representation of a year in 4 digits, "m" provides numeric representation of a month and "t" gives the number of days in the given month.
• By using "Y-m-t", we will get the number of days in a month because of "t", "m" and "Y" will provide the month and the year.
• The last step is to use the date() again with "l" for format and the date achieved above as $timestamp.
• Display the day.

Program:

<?php
 
// Given a date in string format 
$datestring = '2020-04-23';

// Converting string to date
$date = strtotime($datestring);
 
// Last date of current month.
$lastdate = strtotime(date("Y-m-t", $date ));


// Day of the last date 
$day = date("l", $lastdate);

echo $day;
?>

Thursday

Using DateTime Class

In this approach, we utilize the DateTime class in PHP to get the last day of the month. The DateTime class provides a powerful and flexible way to manipulate and format dates. We can take advantage of its methods to achieve the task efficiently.

Example: The following example demonstrates how to use the DateTime class to get the last day of the month and print the day of the week.

<?php
function getLastDayOfMonth($dateString) {
    $date = new DateTime($dateString);
    $date->modify('last day of this month');
    $dayOfWeek = $date->format('l');

    return $dayOfWeek;
}
$inputDate1 = '2020-04-23';
echo getLastDayOfMonth($inputDate1);

$inputDate2 = '2018-09-11';
?>

Thursday