Answer

There are no myths regarding Tuesday being an unlucky day. Believing in myths falls under superstition and superstitious beliefs in Islam amounts to shirk.

Saaiduna Abdullah Ibn Masud Radiallahu Anhu narrates that the Prophet of Allah Sallallahu Alahi Wasalam said: “Tiyarah (superstitious belief in bird omens) is shirk.” (Sunan Abu Dawud p.190 v.2)

Only Allah Knows Best