Morning dress, also known as formal day dress, is the formal Western dress code for day attire, consisting chiefly of a morning coat, waistcoat, and formal trousers for men, and an appropriate gown for women. Men may also wear a popular variant, where all parts (morning coat or waistcoat, and trousers) are the same colour and material, often grey, and usually called "morning suit" or "morning grey" to distinguish it; considered properly appropriate only to festive functions, such as summer weddings and horse races, which consequently makes it slightly less formal. The correct hat would be a formal top hat, or if on less spacious audience settings, optionally a collapsible equivalent opera hat.
Debrett's states that morning dress should not be specified as the dress code for events starting after 6 p.m. If a formal event will commence at or after 6 p.m., white tie should be specified instead. The semi-formal daytime counterpart of this code is the black lounge suit.
