PHP: Use of DateTime Relative Formats for times < or

Does anybody know of an elegant way of using the PHP DateTime relative formats feature well for DateTime's that are not the current time?

Basically - I can create a new DateTime with a RelativeFormat from the current time very easily with

new DateTime('first monday of this week');

It would be incredibly useful to be able to do the same with other dates, so something like either:

new DateTime('first monday of 4 Jun 2022');  -> Should return  30 May 2022

$time = DateTime::createFromFormat('Y-m-d H:i:s', '2022-06-4 12:00:00);
$time->modify('first monday of week') -> Should return 30 May 2022

I know that this could be done with a function that mangles the date with various permutations of strtotime() but if anybody knows of a PHP library or something built into Relative Formats that I haven't found in the documentation which could achieve it more gracefully I'd be very grateful for the pointer.

CodePudding user response：

Your code works you are just missing "... this ..." in the first parameter of ->modify() as you want it to be relative to the DateTime describing that week.

<?php
$time = DateTime::createFromFormat('Y-m-d H:i:s', '2022-06-4 12:00:00');
$time->modify('first monday of this week'); //-> Should return 30 May 2022
var_dump($time);

/*
object(DateTime)#1 (3) {
  ["date"]=>
  string(26) "2022-05-30 00:00:00.000000"
  ["timezone_type"]=>
  int(3)
  ["timezone"]=>
  string(3) "UTC"
}
*/

echo $time->format('d M Y'); // 30 May 2022

Demo on 3v4l.org: https://3v4l.org/nNR7X

Alternatively for the exact values you provide you could have meant ->modify("last monday"); that also returns 30th of May for June 4th this year but it would give you the previous week if the input date is a Monday itself, e.g. June 6th this year.

CodePudding user response：

strtotime function is exactly what you are searching for. It gets reference time as second argument.

viz. https://www.php.net/manual/en/function.strtotime.php

CodePudding user response：

You can use strtotime and date functions:

$time = DateTime::createFromFormat('Y-m-d H:i:s', '2022-06-04 12:00:10');
var_dump(date('M j Y', strtotime('first monday of this week', $time->getTimestamp())));

output:

string(11) "May 30 2022"