Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Jakarta to Aruba as you normally would.
This is defined as Jakarta Soekarno-Hatta Intl Airport (CGK) and Oranjestad Reina Beatrix Airport (AUA). Codes like Oranjestad Reina Beatrix Airport are often used to just call airports uniquely.