Yes when He returns in a white horse is a different event, but acts 1:11 is before the white horse appears:
Zechariah 14:3 Then shall the Lord go forth, and fight against those nations, as when he fought in the day of battle.
4 And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south.
5 And ye shall flee to the valley of the mountains; for the valley of the mountains shall reach unto Azal: yea, ye shall flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah: and the Lord my God shall come, and all the saints with thee.
Matthew 24:16 Then let them which be in Judaea flee into the mountains:
Revelation 12:6 And the woman fled into the wilderness, where she hath a place prepared of God, that they should feed her there a thousand two hundred and threescore days.
-When they saw the abomination of desolation, they fled to the mountains, were Jesus had descended "in like manner" upon the mount of olives, and divided it, to make a way of escape into the wilderness, were they were nourished during the 42 months:
Revelation 12:14 And to the woman were given two wings of a great eagle, that she might fly into the wilderness, into her place, where she is nourished for a time, and times, and half a time, from the face of the serpent.