<?php
    $date = "09/10/2019";
    $date_array = explode("/",$date); // split the array
    $var_day = $date_array[0]; //day seqment
    $var_month = $date_array[1]; //month segment
    $var_year = $date_array[2]; //year segment
    $new_date_format = "$var_year-$var_day-$var_month"; // join them together

    function convertDate($date) {
        // EN-Date to GE-Date
        if (strstr($date, "-") || strstr($date, "/"))   {
                $date = preg_split("/[\/]|[-]+/", $date);
                $date = $date[2]."-".$date[1]."-".$date[0];
                return $date;
        }

        return false;
 }
 echo $date;
 echo "<br>";
 echo convertDate($date);
?>