Students graph the local periods of sunlight and darkness in a 24-hour day using gathered sunrise and sunset times. They make comparisons between periods of sunlight and darkness on different days of the year. The data is represented through bar graphs which are then used to translate the information in to circle graphs showing the amount of time day and night take up in each 24-hour period. Student worksheets included. Example of how to use a physical model with a globe and light to demonstrate Earth’s rotation as the cause for day and night included.