<?php
// Arbitrary dates to find out a day value in int
$dayX = strtotime('Jan 2 2002') - strtotime('Jan 1 2002');
$dayY = strtotime('April 28 1999') - strtotime('April 27 1999');
if ($dayX == $dayY){
    $aDay = $dayX; //$aDay = 86400;

    $date[0] = strtotime('Oct 24 2002');
        print date("M j 'y", $date[0]);
        print '<br>';
  
    for ($i=1; $i<10; $i++){
        $date[$i] = $date[$i-1] + $aDay;
        print date("M j 'y", $date[$i]);
        print '<br>';
    }
}
?>

The code prints

Oct 24 '02
Oct 25 '02
Oct 26 '02
Oct 27 '02
Oct 27 '02
Oct 28 '02
Oct 29 '02
Oct 30 '02
Oct 31 '02
Nov 1 '02

We are happy to tell you that you just discovered Daylight Savings
Time. For more information see:
http://webexhibits.org/daylightsaving/b.html

$ php4/sapi/cli/php -f ./data.php 
86400
Start at: Oct 20 '02
Oct 21 '02 00:00:00 (1035151200 - 1)
Oct 22 '02 00:00:00 (1035237600 - 2)
Oct 23 '02 00:00:00 (1035324000 - 3)
Oct 24 '02 00:00:00 (1035410400 - 4)
Oct 25 '02 00:00:00 (1035496800 - 5)
Oct 26 '02 00:00:00 (1035583200 - 6)
Oct 27 '02 00:00:00 (1035669600 - 7)
Oct 27 '02 23:00:00 (1035756000 - 8)
Oct 28 '02 23:00:00 (1035842400 - 9)