Why does Earth's shape make it arbitrary which countries are considered oriental ?

Question

How did the convention develop as to which countries are considered oriental (East)?

Answer 1

The term "orient" is from the latin word "orientem", meaning "that part of sky where the sun rises". The first use of this term in a geographical sense was in 13th century, denoting the mideast. Note that this is an European convention. Later, China and other Far East countries came under the umbrella of "The Orient". That's how the western convention began. Curiously, though, Japan likes to think of itself as the land of "The Rising Sun". Hmm?

To answer your first question, the Earth is round, so "The East" can be anywhere. If you go towards "The East", you'll never stop.

Answer 2

From the culture of Europe and Greece of course.