Get exact date by providing week number of month and day?

Get exact date by providing week number of month and day?

Is there any php function where i can get exact date, by providing week
number of the month and day as,
function required_date($week_num, $day) {
// should return 20th of September, if i pass (3, 'Friday')
}
I am getting week number of the month as
ceil(substr(date('Y-m-d'), -2) / 7);
and day as,
date('l');
Any help, please!