Is disposing of trash at night impermissible according to Sharia, or is it merely a matter of customs and traditions?

Islam encourages cleanliness and the removal of dirt and waste, without specifying a particular time for it. There are indeed Prophetic traditions that urge cleanliness, such as: "Indeed, Allah is good and loves goodness, clean and loves cleanliness... So clean your courtyards and squares, and do not resemble the Jews." Therefore, there is no religious impediment to removing waste and disposing of it in its designated places at any time.