The lines of longitude also known as the meridian are imaginary lines that run from north to south and measure the position east-west of a point. The lines of longitude are used to determine the time at a location. Below shows the relationship between the change in degrees and time.
1° = 4 minute, 15° = 1 hour
The prime meridian is at 0°. The degree change between the prime meridian and a point 60° east of the meridian = 60°
change in time = 60° * 1 hour / 15° = 4 hour
Time at 60° east of the meridian = Time at the meridian + change in time = 12 pm + 4 hour = 4 pm
