for($i = $begin; $i <= $end; $i->modify('+1 day')){ echo $i->format("Y-m-d"); } code example

Example: php loop through every day of the year

$begin = new DateTime( "2015-07-03" );
$end   = new DateTime( "2015-07-09" );

for($i = $begin; $i <= $end; $i->modify('+1 day')){
    echo $i->format("Y-m-d");
}