//date from a form in the format of dd/mm/yyyy

$date_array = explode("/",$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
$departure = "$var_year-$var_day-$var_month";//join them all together to input into a mysql table

This snippet collects a date from a var and formats it into the correct format for database date entry

Date format for mysql input

mysql, date, format

PHP