What should one do if they repeatedly experience troubling events on Sunday, despite knowing that it is not permissible to be superstitious about any day of the week?

It is not permissible to practice tiyarah (superstitious belief in omens) regarding the days of the week, including the last Wednesday of the month. The hadith: "The last Wednesday of the month is a day of continuous misfortune," is weak and contradicted by the authentic hadith: "Tiyarah is polytheism (shirk)," and "There is no tiyarah."

A Muslim must rely upon Allah, for tiyarah negates reliance on Allah. One should adopt the lawful means of preservation and protection, such as supplication (du'a), adhering to remembrances (adhkar), seeking forgiveness (istighfar), and sending blessings upon the Prophet, peace and blessings be upon him.