Passage
Blow the trumpet in Zion, and sound an alarm in my holy mountain; let all the inhabitants of the land tremble: for the day of Jehovah cometh, for it is at hand;
Blow the trumpet in Zion, and sound an alarm in my holy mountain; let all the inhabitants of the land tremble: for the day of Jehovah cometh, for it is at hand;
Joel 2:1 Blow the trumpet in Zion, and sound an alarm in my holy mountain; let all the inhabitants of the land tremble: for the day of Jehovah cometh, for it is at hand;
Joel 2:2 a day of darkness and gloom, a day of clouds and gross darkness, as the dawn spread upon the mountains; a great people and a strong; there hath not been ever the like, neither shall be any more after them, to the years of generations and generations.
Joel 2:3 A fire devoureth before them, and behind them a flame burneth; the land is as a garden of Eden before them, and behind them a desolate wilderness: yea, and nothing escapeth them.
The verse centers on "blow", "trumpet", "zion", "sound", "alarm", "holy", "mountain", and "inhabitants". It is saying that the verse draws attention to "blow" and "trumpet", so its meaning should be read from those terms before moving to application.
The next verse adds "a day of darkness and gloom a...", so "blow" and "trumpet" should be read forward into that movement. In Joel context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "blow" and "trumpet" with trust shaped by these words, not by a vague optimism outside the passage.