Question

1. If the time is 3:30 at 15° E longitude what is the time at 108 °E longitude ​

Answer 1

Explanation:

Astronomical time is easiest to explain. There are 24 hours in a day and 360 degrees of longitude. Dividing 360 degrees by 24 hours equals 15 degrees per hour. Time gets later as you go east. So 45 degrees east is 30 degrees east of 15 degrees or 2 hours later. This means the time would 11:00 am at 45 degrees east.

Now the hard part. Civil time is based on astronomical time but is frequently adusted along political and geographic lines to keep a country on the same time zone. For example China has 5 astronomical zones but only one official zone centered on Beijing.