How to convert to end of that day in php?

This post converting the date to end of that day in php.

1. Code:

    <?php 
	function convertMySqlDateToEndDay($mysqlDate){
		if (strlen($mysqlDate) <= strlen(("0000-00-00"))) {
			return $mysqlDate . " 23:59:59";
		}
		$mysqlDate = str_replace("00:00:00", "23:59:59", $mysqlDate);
		return $mysqlDate;
	}
	$str = "2022-06-27";
	$str1 = "2022-06-27 00:00:00";
	echo(convertMySqlDateToEndDay($str));
	echo("<br>");
	echo(convertMySqlDateToEndDay($str1));
    ?> 

2. Example:

Input:

"2022-06-27"
"2022-06-27 00:00:00"

Output:

2022-06-27 23:59:59
2022-06-27 23:59:59