Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Fort Smith to Oakland, California as you normally would.
Due to multiple factors, expect to potentially pay more when booking in March. For low rates, September can be a great choice for travel to Oakland, California. Flights to Oakland, California from Fort Smith in September are about $496 on average during September, but can be found for as low as $383.