Question

When it is 10am in place x (90 degree east), what will be the time at 45 degree East longitude?

Answer 1

Answer:

There are 360 degrees of longitude around the earth so with every 24-hour rotation of the earth that is a rate of 15 degrees per hour. Your two longitudes are 30 degrees apart so they will be two hours apart. With the earth rotating from West to East, this makes the time at 45 East 2 hours ahead of that at 15 degrees East. This works for areas with time zone boundaries running due North/South. Many places have deviations in their time zone boundaries to satisfy local politics.