When I travel, Before I pick a seat, I will think about the direction of the bus or plane to decide which side(left or right) seat I should select. Sometimes I like the sun while traveling, sometimes I'm not. The method is simple, it needs three factors, 1. The direction of this transportation tool way to your destination; 2. The time range; 3. The direction of the sun in the time range. So if I create this site, I need these variables first: 1. Tell me where are you going(such as From, To). I can confirm the direction of the transportation tool on Google Maps. 2. Tell me the time, I can calculate the direction of the sun based on the time range. After that, I can know which side seat you should choose.