PHP program to change date format

You are given a string which contain date and time. Date in dd/mm/yyyy format and time in 12 hrs format.You have to convert date in yyyy/mm/dd format and time in 24 hrs format. Examples:

Input : $date = "12/05/2018 10:12 AM"
Output : 2018-05-12 10:12:00

Input : $date = "06/12/2014 04:13 PM"
Output : 2014-12-06 16:13:00

First we will convert date to unix timestamp using strtotime() and then use date() to convert it to a specific format(The strtotime() function parses an English textual datetime into a Unix timestamp (the number of seconds since January 1 1970 00:00:00 GMT)) php

<?php

    // function to convert string and print
    function convertString ($date)
    {
        // convert date and time to seconds
        $sec = strtotime($date);

        // convert seconds into a specific format
        $date = date("Y-m-d H:i", $sec);

        // append seconds to the date and time
        $date = $date . ":00";

        // print final date and time
        echo $date;
    }
    
    // Driver code
    $date = "06/12/2014 04:13 PM";
    convertString($date);
?>