Below are some other words and descriptions of the Day of the Lord
Day of the Trumpet
Zep 1:16 A day of the trumpet and alarm against the fenced cities, and against the high towers. Could this be talking about "the last trump"?
Day of Visitation
Mic 7:4 The best of them is as a brier: the most upright is sharper than a thorn hedge: the day of thy watchmen and thy visitation cometh; now shall be their perplexity.
Day of Calamity
Jer 18:17 I will scatter them as with an east wind before the enemy; I will show them the back, and not the face, in the day of their calamity.
Day of Vengence
Pro 6:34 For jealousy is the rage of a man: therefore he will not spare in the day of vengeance.
Isa 61:2 To proclaim the acceptable year of the LORD, and the day of vengeance of our God; to comfort all that mourn;
Isa 34:8 For it is the day of the LORD's vengeance, and the year of recompenses for the controversy of Zion.
Isa 63:4 For the day of vengeance is in mine heart, and the year of my redeemed is come.
Jer 46:10 For this is the day of the Lord GOD of hosts, a day of vengeance, that he may avenge him of his adversaries: and the sword shall devour, and it shall be satiate and made drunk with their blood: for the Lord GOD of hosts hath a sacrifice in the north country by the river Euphrates.
Day of Slaughter
Isa 30:25 And there shall be upon every high mountain, and upon every high hill, rivers and streams of waters in the day of the great slaughter, when the towers fall.
Jer 12:3 But thou, O LORD, knowest me: thou hast seen me, and tried mine heart toward thee: pull them out like sheep for the slaughter, and prepare them for the day of slaughter.
Day of Evil
Jer 17:17 Be not a terror unto me: thou art my hope in the day of evil.
Amo 6:3 Ye that put far away the evil day, and cause the seat of violence to come near;
Eph 6:13 Wherefore take unto you the whole armor of God, that ye may be able to withstand in the evil day, and having done all, to stand.
Indignation of God
Psa 69:24 Pour out thine indignation upon them, and let thy wrathful anger take hold of them. "Pour out" as in 7 vials?
"Day of the Trumpet" would again indicate that the Day of the Lord begins at the sounding of a trumpet, while "Pour out" indicates that the the Day of the Lord also encompasses the entire 7 vial judgments. The seven vials are "filled up" with the wrath of God.
Rev 15:7 And one of the four beasts gave unto the seven angels seven golden vials full of the wrath of God, who liveth forever and ever.