<?php
// http://stackoverflow.com/questions/13128854/php-datetime-class-change-first-day-of-the-week-to-monday?rq=1
$test = new DateTime('2012-11-04');
// 2012-11-05 // I expect to get 2012-10-29
echo $test->modify('Monday this week')->format('Y-m-d');
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
2012-10-29