The InfiniteIterator class

to loop through object keys and reset to the start, try this:
<?php
$obj = new stdClass();
$obj->Mon = "Monday";
$obj->Tue = "Tuesday";
$obj->Wed = "Wednesday";
$obj->Thu = "Thursday";
$obj->Fri = "Friday";
$obj->Sat = "Saturday";
$obj->Sun = "Sunday";
$infinate = new InfiniteIterator(new ArrayIterator($obj));
foreach ( new LimitIterator($infinate, 0, 14) as $value ) {
 print($value . PHP_EOL);
}
?>

will output:
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Can be useful when doing date operations or recurring events

It is important to realise that rewind() must be called on any iterator before using it or you may experience undefined behaviour, see example code and output here http://3v4l.org/rvNpU
See this bug report https://bugs.php.net/bug.php?id=63823&edit=2 for a fuller explanation.