get all of dates ( day ) from a month...
$month = '2015-01';
$start = Carbon::parse($month)->startOfMonth();
$end = Carbon::parse($month)->endOfMonth();
$dates = [];
while ($start->lte($end)) {
$dates[] = $start->copy();
$start->addDay();
}
echo "<pre>", print_r($dates), "</pre>";