The Seven Year Tribulation will begin with the revealing of the Antichrist

He will be revealed to the discerning Christians by a seven year contract that allows the re-establishment of daily (blood) sacrifice by the Jews (Daniel 9:27).
Daniel 9:27 (NIV) He will confirm a covenant with many for one ‘seven’ but in the middle of that ‘seven’ he will put an end to sacrifice and offering.
And one who causes desolation will place abominations on a wing of the temple until the end that is decreed is poured out on him."

Whoever is able to make the covenant (contract) that allows re-establishment of daily sacrifice is the Antichrist. At that precise moment in time, we will be in the Tribulation.
The seven year clock of the Tribulation will have started.

Daniel 8:9-14 (NIV) Out of one of them came another horn, which started small but grew in power to the south and to the east and toward the Beautiful Land.

10 It grew until it reached the host of the heavens, and it threw some of the starry host down to the earth and trampled on them.

11 It set itself up to be as great as the Prince of the host; it took away the daily sacrifice from him, and the place of his sanctuary was brought low.

12 Because of rebellion, the host of the saints and the daily sacrifice were given over to it. It prospered in everything it did, and truth was thrown to the ground.

13 Then I heard a holy one speaking, and another holy one said to him,
"How long will it take for the vision to be fulfilled--the vision concerning the daily sacrifice, the rebellion that causes desolation, and the surrender of the sanctuary and of the host that will be trampled underfoot?"

14 He said to me, "It will take 2,300 evenings and mornings; then the sanctuary will be reconsecrated."
There are four things listed in Daniel's vision, and a time table given for them:
1."the daily sacrifice"
2."the abomination that causes desolation"
3."the surrender of the sanctuary"
4."the host that will be trampled underfoot"

The time table is "2,300 evenings and mornings."
We operate under the Gregorian calendar of 365 days per year with a leap day every four years. 365 days time 7 years totals 2,555 days.
Daniel operated under the lunar calendar of 12 periods with 30 days, totalling 360 days per year, with a leap month every 7 years. 360 days time 7 years totals 2,520 days.
Since portions of the prophecy of Daniel were written for us, and our understanding, and not for Daniel, and his understanding, we can conclude that the time table in those portions is based on our calendar. We will not know the day or hour for the Second Coming of Jesus Christ, because if for no other reason, we do not know when the leap day will be applied.

There are 2,555 days in the seven year period allocated by Daniel 9:27 for the Tribulation, but only "2,300 evenings and mornings" referenced in Daniel 8:14, for daily sacrifice.
This 255 day time gap, or 8 1/2 months is the time that will be required for the rebuilding of the Temple, after the Antichrist confirms the "covenant."

The "seven" referenced in Daniel 9:27 is the Seven Year Tribulation period spoken of in Jeremiah 30:5-7, and Matthew 24:21-22.

Matthew 24:15 (NIV) "So when you see standing in the holy place 'the abomination that causes desolation,' spoken of through the prophet Daniel--let the reader understand-- Jeremiah 30:5-7 (NIV) "This is what the LORD says: "'Cries of fear are heard-- terror, not peace.

6 Ask and see: Can a man bear children? Then why do I see every strong man with his hands on his stomach like a woman in labour, every face turned deathly pale?

7 How awful that day will be! None will be like it. It will be a time of trouble for Jacob, but he will be saved out of it.

Matthew 24:21-22 (NIV) For then there will be great distress, unequalled from the beginning of the world until now--and never to be equalled again. 22 If those days had not been cut short, no one would survive, but for the sake of the elect those days will be shortened.

We know that Matthew 24:21-22, and Jeremiah 30:5-7 are referencing the Seven Year Tribulation period of Daniel 9:27 because in the middle of that "seven" we have "the abomination that causes desolation" referenced in Matthew 24:15, - the Antichrist setting himself up in the Temple and proclaiming himself God.

<p>Antiochus Epiphanes is a for glimpse of the Antichrist and created an "abomination that causes desolation" when he desecrated the Temple approximately 160 years before Christ, for a 3 1/2 year period. Antiochus Epiphanes was the King of Syria. The King of Syria will be the Antichrist. Hafez Assad, the present King of Syria is the most brilliant, deceptive, and cunning man in the middle east. Hafez Assad's second son Bashar Assad is being groomed to succeed him. When Saddam Hussein attacked Kuwait, Saddam was condemned by a substantial portion of the world.

At the time, when the world was distracted by Saddam, Haffez Assad took complete control of Lebanon by killing all of his Christian resistance. He was not only never questioned by the world, he remained a powerful force in the coalition that attacked Saddam. Syria has long been reported by the C.I.A. as being heavily involved in state-backed international drug trafficking. Haffez Assad has been in control of world terrorism for more than a decade through his control of Hamas, Hezbollah, the P. L. O. and ALL mid-east terrorist organisations, with minimal world condemnation. His puppets have included at various times; King Hussein of Jordan, Yasser Arafat - spokesman for the P.L.O., Moammar Gadhafi - King of Libya, as well as lesser known people, important only in the area of world terrorism.