Here we’ll provide the simplest way to add days to date using PHP. In PHP, using dateadd() function you can easily increase date.

1. Code:

    <?php 
	function dateAddWithFormat($date, $day, $format){
		if (is_null($date) || trim($date) == '' || "0000-00-00 00:00:00" == trim($date)) {
			return null;
		}
		try {
			$d = date_create_from_format($format, $date);
			if (false === $d) {
				throw new \Exception ("Invalid date");
			}
		}catch (\Exception $e) {
			return $dater;
		}
		date_add($d, date_interval_create_from_date_string("$day days"));
		$str = $d->format($format);
		return (false != $str) ? $str : null;
	}
	
	echo(dateAddWithFormat("2022-06-27 01:23:22", 5, "Y-m-d H:i:s"));
    ?> 

2. Example:

Input:

"2022-06-17", 5, "Y-m-d";
"2022-06-27 01:23:22", 5, "Y-m-d H:i:s"

Output:

2022-06-22
2022-07-02 01:23:22