$today = strtotime(date(dny));
$daybefore = $today - 86400;
print date(dny);
print "\n\n $today $daybefore \n\n";
print date(dny,$today);
print "\n\n";
print date(dny,$daybefore);



gives:
11906

 1025935200 1025848800

06702

05702