Question

Give geigraphical reason of the local time is decided by the noon time.

Answer 1

there are three events in a day that are easily observable: sunrise, sunset and noon. In most parts of the world, sunrise and sunset are long-drawn-out things. For example, take Madrid, roughly in the middle of the longitude range for the Western world and look at . Today (22 July) the sunrise has three different times (astronomical twilight, nautical twilight and civil twiight), at 5:07, 5:52 and 6:31. That’s a difference of nearly 1½ hours, and it happens again at sunset (22:10 to 23:33). So sunrise and sunset aren’t useful. That leaves noon, which can be measured relatively accurately.