modify('first day of this month')->format('Y-m-d');
$endDate = $date->modify('last day of this month')->format('Y-m-d');
$datesInMonth = [];
$period = new DatePeriod(
new DateTime($startDate),
new DateInterval('P1D'),
(new DateTime($endDate))->modify('+1 day')
);
foreach ($period as $day) {
$datesInMonth[] = $day->format('Y-m-d');
}
?>