Finding Last Day of Previous Month in PHP - php

Question

I'm a little unsure why this is not able to find the last day of the previous month. Every steps seems to be working correctly, except when the final date is created.
<?php
$currentMonth = date('n');
$currentYear = date('Y');
if($currentMonth == 1) {
$lastMonth = 12;
$lastYear = $currentYear - 1;
}
else {
$lastMonth = $currentMonth -1;
$lastYear = $currentYear;
}
if($lastMonth < 10) {
$lastMonth = '0' . $lastMonth;
}
$lastDayOfMonth = date('t', $lastMonth);
$lastDateOfPreviousMonth = $lastYear . '-' . $lastMonth . '-' . $lastDayOfMonth;
$newLastDateOfMonth = date('F j, Y', strtotime($lastDateOfPreviousMonth));
?>
$lastDateOfPreviousMonth is returning 2012-09-30 as expected; however, after trying to convert it to September 30, 2012 - $newLastDateOfMonth is returning October 1, 2012. Where do I seem to be going wrong?
EDIT: If using date("t/m/Y", strtotime("last month")); or date('Y-m-d', strtotime('last day of previous month')); will either of these still be viable given 2013-01-01, i.e. will they account for the change in year?

Answer 1

echo date('Y-m-d', strtotime('last day of previous month'));
//2012-09-30
or
$date = new DateTime();
$date->modify("last day of previous month");
echo $date->format("Y-m-d");
Later edit: php.net documentation - relative formats for strtotime(), DateTime and date_create()

Answer 2

There is a php function for this.
echo date("t/m/Y", strtotime("last month"));

Answer 3

First day of this month, minus 1 second.
echo date('Y-m-d',strtotime('-1 second',strtotime(date('m').'/01/'.date('Y'))));
Example here.

Answer 4

please try with below answer.
code:
echo date("t/m/Y", strtotime(date('Y-m')." -1 month"));
You will get last day of previous 12 months.
Example:
<?php
for ($i = 1; $i <= 12; $i++) {
$months[] = date("t/m/Y l", strtotime(date('Y-m')." -$i months"));
}
print_r($months);
?>
Output:
Array
(
[0] => 30/11/2018 Monday
[1] => 31/10/2018 Friday
[2] => 30/09/2018 Wednesday
[3] => 31/08/2018 Sunday
[4] => 31/07/2018 Thursday
[5] => 30/06/2018 Tuesday
[6] => 31/05/2018 Saturday
[7] => 30/04/2018 Thursday
[8] => 31/03/2018 Monday
[9] => 28/02/2018 Monday
[10] => 31/01/2018 Friday
[11] => 31/12/2017 Tuesday
)

Answer 5

You can use strtotime()'s zero handling functionality to achieve this also:
# Day Before
echo date('Y-m-d', strtotime('2016-03-00')); // 2016-02-29
# Year can be handled too
echo date('Y-m-d', strtotime('2016-01-00')); // 2015-12-31
# Month Before
echo date('Y-m-d', strtotime('2016-00-01')); // 2015-12-01
# Month AND Day
echo date('Y-m-d', strtotime('2016-00-00')); // 2015-11-30
Makes sense if you think of 00 as 'one less than the first (01)'.
So to achieve the objective of this question, 'last day of previous month' is a simple case of
date('your_format', strtotime('YYYY-ThisMonth-00'));
# So:
date('Y-m-d', strtotime('2016-11-00')); // 2016-10-31