Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Penang to Tromsø as you normally would.
PEN and TOS are unique codes to identify airports used in the aviation industry. They are defined by IATA (International Air Transport Association) and are commonly called IATA codes. PEN to TOS refers to a flight route from Penang Intl Airport to Tromso/Langnes Airport.