[php] How can I find the first and last date in a month using PHP?

How can I find the first and last date in a month using PHP? For example, today is April 21, 2010; I want to find April 1, 2010 and April 30, 2010.

For specific month and year use date() as natural language as following

$first_date = date('d-m-Y',strtotime('first day of april 2010'));
$last_date = date('d-m-Y',strtotime('last day of april 2010'));
// Isn't it simple way?

but for Current month

$first_date = date('d-m-Y',strtotime('first day of this month'));
$last_date = date('d-m-Y',strtotime('last day of this month'));

If you want to find the first day and last day from the specified date variable then you can do this like below:

$date    =    '2012-02-12';//your given date

$first_date_find = strtotime(date("Y-m-d", strtotime($date)) . ", first day of this month");
echo $first_date = date("Y-m-d",$first_date_find);

$last_date_find = strtotime(date("Y-m-d", strtotime($date)) . ", last day of this month");
echo $last_date = date("Y-m-d",$last_date_find);

For the current date just simple use this

$first_date = date('Y-m-d',strtotime('first day of this month'));
$last_date = date('Y-m-d',strtotime('last day of this month'));

Simple one

• Y - A full numeric representation of a year, 4 digits
• m - Numeric representation of a month, with leading zeros
• t - Number of days in the given month

Reference - http://www.php.net/manual/en/function.date.php

<?php
    echo 'First Date    = ' . date('Y-m-01') . '<br />';
    echo 'Last Date     = ' . date('Y-m-t')  . '<br />';
?>

To get the first and last date of Last Month;

$dateBegin = strtotime("first day of last month");  
$dateEnd = strtotime("last day of last month");

echo date("D-F-Y", $dateBegin);  
echo "<br>";        
echo date("D-F-Y", $dateEnd);

You can use the date function to find how many days in a month there are.

// Get the timestamp for the date/month in question.
$ts = strtotime('April 2010');

echo date('t', $ts); 
// Result: 30, therefore, April 30, 2010 is the last day of that month.

Hope that helps.

EDIT: After reading Luis' answer, it occurred to me you may want it in the right format (YY-mm-dd). It may be obvious, but doesn't hurt to mention:

// After the above code
echo date('Y-m-t', $ts); 

This will give you the last day of the month:

function lastday($month = '', $year = '') {
   if (empty($month)) {
      $month = date('m');
   }
   if (empty($year)) {
      $year = date('Y');
   }
   $result = strtotime("{$year}-{$month}-01");
   $result = strtotime('-1 second', strtotime('+1 month', $result));
   return date('Y-m-d', $result);
}

And the first Day:

function firstDay($month = '', $year = '')
{
    if (empty($month)) {
      $month = date('m');
   }
   if (empty($year)) {
      $year = date('Y');
   }
   $result = strtotime("{$year}-{$month}-01");
   return date('Y-m-d', $result);
} 

$month=01;
$year=2015;
$num = cal_days_in_month(CAL_GREGORIAN, $month, $year);
echo $num;

display 31 last day of date

In simple format

   $curMonth = date('F');
   $curYear  = date('Y');
   $timestamp    = strtotime($curMonth.' '.$curYear);
   $first_second = date('Y-m-01 00:00:00', $timestamp);
   $last_second  = date('Y-m-t 12:59:59', $timestamp); 

For next month change $curMonth to $curMonth = date('F',strtotime("+1 months"));

You can use DateTimeImmutable::modify() :

$date = DateTimeImmutable::createFromFormat('Y-m-d', '2021-02-13');

var_dump($date->modify('first day of this month')->format('Y-m-d')); // string(10) "2021-02-01"
var_dump($date->modify('last day of this month')->format('Y-m-d')); // string(10) "2021-02-28"