Zechariah 14 Is Not About The Second Coming

On that day His feet will stand on the Mount of Olives,which faces Jerusalem on the east. The Mount of Olives will be split in half from east to west, forming a huge valley, so that half the mountain will move to the north and half to the south. 
-Zechariah 14:4

I saw this idea, presented by someone, that Jesus' feet would 'touch down' on the Mount of Olives, some day, in the future, at his second coming.  I grew up in a local church that strongly taught dispensationalism, which I do not believe in today.  Here is what I do believe.

Zechariah 14 is not about the second coming.  The day of the Lord, spoken of in verse 1, is not the end of the world, but a judgement day.  And when that judgement day came and the Lord's feet touched the Mount of Olives, that was not the second coming, as we conceive of it today, but it happened around 70 A.D., when Jerusalem was destroyed.

Zechariah 13 does talk about Jesus:
Sword, awake against My shepherd,
against the man who is My associate—
this is the declaration of the Lord of Hosts.
Strike the shepherd, and the sheep will be scattered;
I will also turn My hand against the little ones. (13:7)
There will be a judgement, and 1/3 will survive it, as a remnant.  Messiah will be crucified, then judgement will come upon Israel.
In the whole land—this is the Lord’s declaration—
two-thirds will be cut off and die,
but a third will be left in it.
I will put this third through the fire;
I will refine them as silver is refined
and test them as gold is tested.
They will call on My name,
and I will answer them.
I will say: They are My people,
and they will say: Yahweh is our God. (13:8-9)
Jesus taught that this would happen, in his parables in Matthew 21 and 22:

The Parable of the Vineyard Owner

“Listen to another parable: There was a man, a landowner, who planted a vineyard, put a fence around it, dug a winepress in it, and built a watchtower. He leased it to tenant farmers and went away. When the grape harvest drew near, he sent his slaves to the farmers to collect his fruit. But the farmers took his slaves, beat one, killed another, and stoned a third. Again, he sent other slaves, more than the first group, and they did the same to them. Finally, he sent his son to them. ‘They will respect my son,’ he said.
“But when the tenant farmers saw the son, they said among themselves, ‘This is the heir. Come, let’s kill him and take his inheritance!’ So they seized him, threw him out of the vineyard, and killed him. Therefore, when the owner of the vineyard comes, what will he do to those farmers?”
“He will completely destroy those terrible men,” they told Him, “and lease his vineyard to other farmers who will give him his produce at the harvest.”
Jesus said to them, “Have you never read in the Scriptures:

The stone that the builders rejected
has become the cornerstone.
This came from the Lord
and is wonderful in our eyes?
Therefore I tell you, the kingdom of God will be taken away from you and given to a nation producing its fruit. [Whoever falls on this stone will be broken to pieces; but on whoever it falls, it will grind him to powder!]” (Matt. 21:33-44)

The Parable of the Wedding Banquet
Once more Jesus spoke to them in parables: “The kingdom of heavenmay be compared to a king who gave a wedding banquet for his son. He sent out his slaves to summon those invited to the banquet, but they didn’t want to come. Again, he sent out other slaves, and said, ‘Tell those who are invited: Look, I’ve prepared my dinner; my oxen and fattened cattle have been slaughtered, and everything is ready. Come to the wedding banquet.’
“But they paid no attention and went away, one to his own farm, another to his business. And the others seized his slaves, treated them outrageously and killed them. The king was enraged, so he sent out his troops, destroyed those murderers, and burned down their city.
“Then he told his slaves, ‘The banquet is ready, but those who were invited were not worthy. Therefore go to where the roads exit the city and invite everyone you find to the banquet.’ So those slaves went out on the roads and gathered everyone they found, both evil and good. The wedding banquet was filled with guests. But when the king came in to view the guests, he saw a man there who was not dressed for a wedding. So he said to him, ‘Friend, how did you get in here without wedding clothes?’ The man was speechless.
“Then the king told the attendants, ‘Tie him up hand and foot, and throw him into the outer darkness, where there will be weeping and gnashing of teeth.’
“For many are invited, but few are chosen.” (Matt. 22:1-14)
The end of Zechariah 13 gives us the backdrop or context for chapter 14.  The time period is the time of the coming of Messiah and his death, and what happens after that, which is the judgement of Israel.
A day of the Lord is coming when your plunder will be divided in your presence. (Zech. 14:1)
This is a judgement day, not the end of the world.  This is what "day of the Lord" means in the Bible.
I will gather all the nations against Jerusalem for battle. The city will be captured, the houses looted, and the women raped. Half the city will go into exile, but the rest of the people will not be removed from the city. (Zech 14:2)
"All the nations", is hyperbole, for Rome, Roman soldiers attacking Jerusalem, earthy Jerusalem.  Roman soldiers came from many nations that Rome had conquered, and not just Italy.  The word "half" is figurative, as the "two-thirds" and "one-third" in chapter 13 were also figurative.

Please notice that the writer of Hebrews calls the church Jerusalem or the heavenly Jerusalem:
Instead, you have come to Mount Zion, to the city of the living God (the heavenly Jerusalem), to myriads of angels in festive gathering, to the assembly of the firstborn whose names have been written in heaven, to God who is the Judge of all, to the spirits of righteous people made perfect,  to Jesus (mediator of a new covenant), and to the sprinkled blood, which says better things than the blood of Abel. (Heb. 12:22-24)
In the new covenant, Jerusalem is the people of God, ethnic Jew and Gentile.

Continuing with Zechariah 14:
Then the Lord will go out to fight against those nations as He fights on a day of battle. (Zech. 14:3)
This is the gospel waring against nations to gain back people who are lost.
On that day His feet will stand on the Mount of Olives, which faces Jerusalem on the east. The Mount of Olives will be split in half from east to west, forming a huge valley, so that half the mountain will move to the north and half to the south. (Zech 14:4)
The reference here, of the Lord's feet on the Mount of Olives, is from Ezekiel 11:23:
The glory of the Lord rose up from within the city and stood on the mountain east of the city.
The Lord, God, or Yahweh left Jerusalem, and stopped protecting it, and went east, to the Mount of Olives.

The Mount of Olives splitting in two (Zech. 14:4) is apocalyptic language about God making a way of escape, for the remnant, that escaped the Romans in 70 A.D.  This is symbolic speech, just like John the Baptist saying, "Every valley shall be filled in and every mountain and hill shall be made low", quoting Isaiah 40.
You will flee by My mountain valley, for the valley of the mountains will extend to Azal. You will flee as you fled from the earthquake in the days of Uzziah king of Judah. Then the Lord my God will come and all the holy ones with Him. (Zech. 14:5)
This is the way of escape, made in A.D. 70, for the believers in Jerusalem, who are the new remnant of the people of God.

From verse 6 and following, Jerusalem is now the church, in apocalyptic terms:
On that day there will be no light; the sunlight and moonlight will diminish.  It will be a day known only to Yahweh, without day or night, but there will be light at evening.
On that day living water will flow out from Jerusalem, half of it toward the eastern sea and the other half toward the western sea, in summer and winter alike.  On that day Yahweh will become King over all the earth—Yahweh alone, and His name alone.  All the land from Geba to Rimmon south of Jerusalem will be changed into a plain. But Jerusalem will be raised up and will remain on its site from the Benjamin Gate to the place of the First Gate, to the Corner Gate, and from the Tower of Hananel to the royal winepresses.  People will live there, and never again will there be a curse of complete destruction. So Jerusalem will dwell in security. (Zech. 14:6-11)
We then have a description of how the enemies of God are judged and defeated, in figurative, apocalyptic language:
This will be the plague the Lord strikes all the peoples with, who have warred against Jerusalem: their flesh will rot while they stand on their feet, their eyes will rot in their sockets, and their tongues will rot in their mouths.  On that day a great panic from the Lord will be among them, so that each will seize the hand of another, and the hand of one will rise against the other.  Judah will also fight at Jerusalem, and the wealth of all the surrounding nations will be collected: gold, silver, and clothing in great abundance.  The same plague as the previous one will strike the horses, mules, camels, donkeys, and all the animals that are in those camps. (Zech. 14:12-15)
The end of the chapter now views the church, the people of God, from another angle: a spiritual feast of tabernacles.  And everything in the church, is now holy:
Then all the survivors from the nations that came against Jerusalem will go up year after year to worship the King, the Lord of Hosts, and to celebrate the Festival of Booths.  Should any of the families of the earth not go up to Jerusalem to worship the King, the Lord of Hosts, rain will not fall on them.  And if the people of Egypt will not go up and enter, then rain will not fall on them; this will be the plague the Lord inflicts on the nations who do not go up to celebrate the Festival of Booths.  This will be the punishment of Egypt and all the nations that do not go up to celebrate the Festival of Booths.
On that day, the words

will be on the bells of the horses. The pots in the house of the Lord will be like the sprinkling basins before the altar.  Every pot in Jerusalem and in Judah will be holy to the Lord of Hosts. Everyone who sacrifices will come and take some of the pots to cook in. And on that day there will no longer be a Canaanite in the house of the Lord of Hosts. (Zech. 14:16-21)
Zechariah 14 is about the judgement on Jerusalem in the first century that Jesus said was coming.  It is also about the people of God and the nations, during the time after Messiah's coming, which includes the first century, up through today.

When Rome came to destroy Jerusalem, around 70 A.D., the remnant, the people of God, or the church in Jerusalem escaped to the east, before it was too late.  Zechariah saw the escape plan in advance.  And the church or the people of God are now figuratively, Jerusalem and Israel.

There is one people of God, one in Christ, and we are also hopeful that all ethnic Jews will be saved before the end; but there is only one way to be saved, through Christ, Messiah.  There is only one mediator, only one living way.  We all who are in Christ are living our stories in God's story of loving and saving the world.  Our task is to find meaning in the story of God that we find ourselves in, and to celebrate that together, while inviting the world around us to join.