Prova questo:
SELECT *
FROM guest g inner join reservation r on g.nric = r.guestNric
WHERE arrivalDate = DATE(DATE_ADD(NOW(), INTERVAL +2 DAY))
Prova questo:
SELECT *
FROM guest g inner join reservation r on g.nric = r.guestNric
WHERE arrivalDate = DATE(DATE_ADD(NOW(), INTERVAL +2 DAY))