Double fulfillment for one thing. Very common in scripture.Here's the Zechariah verse you quoted and the scripture plainly stating when this prophecy was fulfilled.
Zechariah 12:10
And I will pour upon the house of David, and upon the inhabitants of Jerusalem, the spirit of grace and of supplications: and they shall look upon me whom they have pierced, and they shall mourn for him, as one mourneth for his only son, and shall be in bitterness for him, as one that is in bitterness for his firstborn.
John 19:31-36
The Jews therefore, because it was the preparation, that the bodies should not remain upon the cross on the sabbath day, (for that sabbath day was an high day,) besought Pilate that their legs might be broken, and that they might be taken away.Then came the soldiers, and brake the legs of the first, and of the other which was crucified with him.But when they came to Jesus, and saw that he was dead already, they brake not his legs:But one of the soldiers with a spear pierced his side, and forthwith came there out blood and water.And he that saw it bare record, and his record is true: and he knoweth that he saith true, that ye might believe.For these things were done, that the scripture should be fulfilled, A bone of him shall not be broken.And again another scripture saith, They shall look on him whom they pierced.
For another thing, CONTEXT is "end times"....IN THAT DAY.
Every time the term IN THAT DAY is used, it always points to the future judgements leading to the Second Coming.
Furthermore there are HUNDREDS of prophecies of similar nature from Genesis to Deuteronomy to Revelation AND in the NT in massive
quantities that have yet to be fulfilled.
Furthermore (and crucially) Seven Feasts of Moses prophetic pattern HAS NOT yet been fulfilled.
The preterist crowd always has been wrong and always will be. Due to Biblical illiteracy.