And ye shall flee [by] the valley of my mountains; for the valley of the mountains shall reach unto Azal: ye shall even flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah. And Jehovah my God shall come, [and] all the holy ones with thee.
Zechariah 14:3 And Jehovah will go forth and fight with those nations, as when he fought in the day of battle.
Zechariah 14:4 And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem toward the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south.
Zechariah 14:5 And ye shall flee [by] the valley of my mountains; for the valley of the mountains shall reach unto Azal: ye shall even flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah. And Jehovah my God shall come, [and] all the holy ones with thee.
Zechariah 14:6 And it shall come to pass in that day, [that] there shall not be light; the shining shall be obscured.
Zechariah 14:7 And it shall be one day which is known to Jehovah, not day, and not night; and it shall come to pass, at eventide it shall be light.
The verse centers on "shall", "flee", "valley", "mountains", and "reach". It is saying that the verse draws attention to "shall" and "flee", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 4's "And his feet shall stand in that..." into verse 6's "And it shall come to pass in...", so "shall" and "flee" belong inside that flow. In Zechariah context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "shall" and "flee" with trust shaped by these words, not by a vague optimism outside the passage.