how global time based on longitude and latitude is worked out please exemplify based on degree latitude?

Question

clarifications: earth total degrees is worked out as 360. this 360 degrees divided by 24 hrs work out will be 15 degree per hour. such workout examples for clarity may plese be supplied

Answer 1

You mentioned latitude as well as longitude. The 24 time zones (ignoring local variations) are based on degrees of longitude, each differing by 15 degrees, as you point out. And, when you consider that the earth rotates 15 degrees per hour regardless of latitude, then you'd say global time is independent of latitude.

But there's at least one way latitude does affect time. Imagine you're in a slow-moving airplane circling the earth from west to east at a constant rate of 100 miles per hour. Also imagine that you have a clock onboard that you always adjust to local time as you circle around.

At the equator (zero degrees latitude), the earth's circumference is about 25,000 miles, and each time zone is a bit over 1000 miles wide (25,000 divided by 24). At 100 mph, you change time zones every 10 hours.

Now consider that, instead of the equator, you fly west to east at some high latitude, perhaps passing through Norway. There, the circumference of your circle (no longer a "great circle") might be 12,000 miles. There are still 24 time zones, so each one is only 500 miles wide, and at 100 mph, you'll change time zones every 5 hours.

At the poles, of course, the time zones mean nothing.

This is one way to look at it to see how latitude, as well as longitude, affects the global system of time zones. The calculation involves the radius of the earth, about 3960 miles, and the cosine of the latitude (a trig function).

Answer 2

You have the basic idea and I believe that the exceptions to the rule are more political.