Finding the date for 29th last month, two months ago, etc - php

Question

I'm looking to find the date of the 29th of this month, the 29th of next month, the 29th of last month and so on...
I know you can use this kind of code to find days of the week:
$friday_last = date("d/m/Y", strtotime("last Friday"));
$friday_due = date("d/m/Y", strtotime("this Friday"));
Is there a similar way to find a certain day (29th) of each month or would I have to use a different code?

Answer 1

You need to use DateTime() as it makes working with dates much easier. You'll notice I start by going to the first day of each month. That's so this doesn't break when you get to the 29th-30th of each month as weird date things start to happen.
echo (new DateTime())->modify('first day of this month')->format("29/m/Y");
echo (new DateTime())->modify('first day of previous month')->format("29/m/Y");
echo (new DateTime())->modify('first day of next month')->format("29/m/Y");
Demo
echo (new DateTime())->modify('first day of this month')->modify('-2 months')->format("29/m/Y");
Demo

Answer 2

Using date() with strtotime() will gives you 29th from each month within this year:
<?php
for ($i = 1; $i <= 12; $i++) {
$d = "2016-" . $i . "-29";
echo "29th of Month $i is: " . date("l", strtotime($d)) . '<br>';
}
?>
Output:
29th of Month 1 is: Friday
29th of Month 2 is: Monday
29th of Month 3 is: Tuesday
29th of Month 4 is: Friday
29th of Month 5 is: Sunday
29th of Month 6 is: Wednesday
29th of Month 7 is: Friday
29th of Month 8 is: Monday
29th of Month 9 is: Thursday
29th of Month 10 is: Saturday
29th of Month 11 is: Tuesday
29th of Month 12 is: Thursday

Answer 3

To create an array with current and next 11 months 29th day (for previous months replace +1 month with -1 month. In this example I use +1 to explain february issue, that is not present in past february):
$baseDate = date_create()->modify( 'first day of this month' );
$dates = array();
for( $i = 0; $i<12; $i++ )
{
$newDate = clone $baseDate;
$dates[] = $newDate->modify( '+28 days' );
$baseDate->modify( '+1 month' );
}
The problem — as you can imagine — is with february:
foreach( $dates as $date )
{
echo $date->format( 'Y-m-d' ).PHP_EOL;
}
Will output:
2016-05-29
2016-06-29
2016-07-29
2016-08-29
2016-09-29
2016-10-29
2016-11-29
2016-12-29
2017-01-29
2017-03-01 <-----
2017-03-29
2017-04-29
If you want a result like “29th month's day OR last month's day” modify above for loop in this way:
for( $i = 0; $i<12; $i++ )
{
$newDate = clone $baseDate;
if( $newDate->modify( '+28 days' )->format( 'm' ) != $baseDate->format( 'm' ) )
{
$newDate->modify( 'last day of previous month' );
}
$dates[] = $newDate;
$baseDate->modify( '+1 month' );
}
Result:
2016-05-29
2016-06-29
2016-07-29
2016-08-29
2016-09-29
2016-10-29
2016-11-29
2016-12-29
2017-01-29
2017-02-28 <-----
2017-03-29
2017-04-29

Answer 4

I'm not sure when this started, but now you can do so by using just date() and strtotime(), like this:
$d = date("Y-m-d 00:00:00", strtotime('first day of 2 months ago'));
$l = date("Y-m-d 00:00:00", strtotime('last day of 2 months ago'));
print_r($d);
print_r($l);
Assuming today (2023-02-01) The above will display:
2022-12-01 00:00:00
2022-12-31 00:00:00
Sample:
https://onlinephp.io/c/db73f