Official sunrise is when the day starts and it is defined by when the sun starts to break the horizon. Before this time there exists different stages of dawn starting with astronomical dawn, going into nautical dawn and ending with civil dawn before the actual sunrise. These stages of dawn are defined by how close the sun is to breaking the horizon.
The same goes for sunset, but all in reverse order. The official sunset is when the last part of the sun disappears under the horizon and following that are different stages of dusk until it is completely dark.
The experience of the sunrise and sunset can vary depending on atmospherical conditions, weather conditions and landscape features. Thus calculated sunrise and sunset times will be an estimate based on average conditions and assuming that no landscape features block the horizon. Idi na
