1) Is Jesusâ€™ coming to gather his chosen ones considered to be the day of the Lord? No but maybe immediately before, that is when signs start appearing in the sky, with the sun being darkened, etc. once the GT is over (compare Mat.24:29, Yoel 2:2,31 and Is. 13:9-13). I think that it may start when Babylon is devastated (Is13:11) and the Antichrist, its king, unmasked (2 Thess.2:3). That is when Jehovah intervenes and starts punishing the nations, Babylon being the first. I found something interesting. Please compare : "Before it [the] land has become agitated, [the] heavens have rocked. Sun and moon themselves have become dark, and the very stars have withdrawn their brightness." - Joel 2:10 Here, "it" stands for "the people" in verse 2 and 5 ("it"). Joel 2:10 NASU Before them the earth quakes, The heavens tremble, The sun and the moon grow dark And the stars lose their brightness. Joel 2:10 The earth quakes as they advance, and the heavens tremble. The sun and moon grow dark, and the stars no longer shine. Holy Bible, NLT "As they come on, the earth quakes, the skies tremble, sun and moon grow dark, the stars lose their brilliance." - Joel 2:10 Jerusalem Bible That's funny because the French version of the Jerusalem Bible says : Before it, the earth quakes... Here, "it" stands also for "the people" in verse 2. The Osty Bible, the Louis Segond Bible say "it" too. Please compare with the earthquake mentioned in Rv11:13. 2) What is the day of Jehovah? The same as the day of the Lord. I've got work to do. Sorry, I can't go any further into my research by now.