Preparation for the tribulation.

The OT ended at John the Baptist.

The old covenant was not fully over until the destruction of Jerusalem and the temple.
There existed an intercovenantal period in the 1st century in which the new covenant is emerging and the old covenant is waning.

No, the first covenant was over when Christ died. The transition you speak of was man's slowness in understanding that. Man still clings to that dead covenant today!

A covenant isn't over until every part of the covenant is fulfilled. There were still sanctions for the nation Israel for not keeping the stipulations of the old covenant yet to come after the cross.
Hebrews 8:13 says it was obsolete and ready to vanish; not gone.

I think it was over either when Peter baptized Cornelius (Acts 10), which marked the end of the 7-year period in which Christ made firm the new covenant with the house of Israel (IMO), or in 70AD when Jerusalem was destroyed.

I choose the latter because while the new covenant did make the old obsolete, all that the old covenant called for had yet to be executed.
I believe this is reflected in the language of Hebrews 8:13.

The old covenant was not fully over until the destruction of Jerusalem and the temple.
There existed an intercovenantal period in the 1st century in which the new covenant is emerging and the old covenant is waning.

A covenant isn't over until every part of the covenant is fulfilled.

Jesus said, "the law and the prophets were until John".
The OT ended with JTB.

Accomplished on the cross. Not to mention the covenant was broken by Israel and God long before.

God never broke the covenant.

Curious, can a covenant end before all that it requires be fulfilled?

Scripture says God did break the covenant.



Of course.

What terms of the covenant did God break?

No terms were broken. He broke the covenant itself.

No. He brought the covenant to conclusion under the terms of the covenant.

Zechariah 11:4 Thus saith the LORD my God; Feed the flock of the slaughter;
Zechariah 11:5 Whose possessors slay them, and hold themselves not guilty: and they that sell them say, Blessed be the LORD; for I am rich: and their own shepherds pity them not.
Zechariah 11:6 For I will no more pity the inhabitants of the land, saith the LORD: but, lo, I will deliver the men every one into his neighbour's hand, and into the hand of his king: and they shall smite the land, and out of their hand I will not deliver them.
Zechariah 11:7 And I will feed the flock of slaughter, even you, O poor of the flock. And I took unto me two staves; the one I called Beauty, and the other I called Bands; and I fed the flock.
Zechariah 11:8 Three shepherds also I cut off in one month; and my soul lothed them, and their soul also abhorred me.
Zechariah 11:9 Then said I, I will not feed you: that that dieth, let it die; and that that is to be cut off, let it be cut off; and let the rest eat every one the flesh of another.
Zechariah 11:10 And I took my staff, even Beauty, and cut it asunder, that I might break my covenant which I had made with all the people.
Zechariah 11:11 And it was broken in that day: and so the poor of the flock that waited upon me knew that it was the word of the LORD.

The covenant being broken by God, but only after the people broke it first.

The term break there means to annul the covenant. To break the covenant, God would need to violate the terms of the covenant. This He is incapable of doing.

and expose his lies.

He still broke the covenant as I have proven. I never said he violated anything.