disponibilita.php

$requete = $database->select(
	'embassy_calendario',
	[
	  "embassy_calendario.id_stanza",
    "embassy_calendario.id_insegnante"
	],
  " WHERE
    (start >= '".date("Y-m-d H:i:s", strtotime($_POST['start']))."' AND start < '".date("Y-m-d H:i:s", strtotime($_POST['end']))."') OR
    (end > '".date("Y-m-d H:i:s", strtotime($_POST['start']))."' AND end <= '".date("Y-m-d H:i:s", strtotime($_POST['end']))."') OR
    (start >= '".date("Y-m-d H:i:s", strtotime($_POST['start']))."' AND end <= '".date("Y-m-d H:i:s", strtotime($_POST['end']))."') OR
    (start < '".date("Y-m-d H:i:s", strtotime($_POST['start']))."' AND end > '".date("Y-m-d H:i:s", strtotime($_POST['end']))."')
  "
);

// sending the encoded result to success page
echo json_encode($requete);