I have recently noticed that there is a huge variation between sunrise and sunset timings when it comes to different latitudes. Take an Example of London, UK and Valencia, Spain. As on today (20 Jun 2015), the sunrise in London is at 4:43 am and is 6:34 am in Valencia (1h 51m difference)... But when it comes to the sunset, London's Sunset is at 21:21 pm while Valencia is at 21:32 pm ( mere 11m difference). Considering that both of them are at the same longitude (but at different latitudes), why is London getting sunlight 2 hours ahead of Valencia but the sun is setting with a mere 11 minutes difference? Shouldn't these two be almost proportional? As I understand, the longitude which carries London & Valencia should face the sun and face away from the sun at same time and the difference in sunset and sunrise timings should be equal. I have noticed the same trend in all other places. the difference between sunrise timings keeps increasing with distance along longitudes, while the sunset timings seem to be almost identical regardless of distance along longitudes ... why is that?