Days and Years

pic   Ian Britton - Freefoto.com

How much time passes between sunrise and sunset? Obviously this varies throughout the year. In winter the sun rises later in the day and sets earlier. We should understand these patterns. Below is a download link to a spreadsheet of sunrise and sunset times. You are going to analyse this data looking for patterns. We will then explain these patterns in terms of the relative motion of the Sun and Earth.

Right click HERE and choose "save target as" to download an Excel file of sunrise and sunset times in London in 2005.

Use this data to produce the following graphs.

1. How sunrise time varied throughout the year.

2. How sunset time varied thought the year.

3. How the number of daylight hours varied throughout the year.

From these graphs and/or the data find

a) Which was the longest day?  b) Which was the shortest? c) Which two days had 12 hours of daylight?

What is daylight saving?  Why was it introduced?