When is Oedipus king in 'Oedipus Rex'?

Answer 1

Three (3) generations before the Trojan War is when Oedipus is King of Thebes in the play "Oedipus Rex" by Sophocles (495 B.C.E. -- 405 B.C.E.).

Specifically, Theban King Oedipus' grandson Thersander lives at the time of the Trojan War. Various dates are given to the timing of that war. But one of the convincing dates is just before 800 B.C.E. The reason for this date is the friendship between Trojan hero Aeneas and Dido of Carthage, an actual, real-life historical person from around 800 B.C.E.