Example of breaking a second.

test.php

<?php
while(true){
    $start = time();
    // Sleeps below are not even necessary.
    // time_nanosleep(0,1);
    //or can use usleep(1); 
    $end = strtotime('1 week');
    if($end-$start > 604800)
    {
        echo "Failed!! ".date('Y-m-d H:i:s',$start).' vs '.date('Y-m-d H:i:s',$end).' start: '.$start.' end: '.$end;
        exit;
    }
}