Great Tribulation Begins April 6, 2009

In your spirit you know something big is about to happen. The earth has begun its death spiral: more floods, more tornadoes, more hurricanes, more earthquakes, and more volcanic eruptions. Though there are still pockets of peace and sanity, most human institutions have disintegrated. You thought you'd be raptured before the Great Tribulation, but now you find yourself in the midst of it.
John, the apostle, taught believers in Jesus would go through the Great Tribulation and many would be martyred in Revelation. Jesus, Paul and Peter all taught believers would have to persevere through great trial and that the dead are resurrected prior to the living being raptured at Christ's one and only return to earth. They all warned us not to be deceived. Keep believing in Jesus even though you have to stop believing in a pre-trib rapture.

3Knowing this first, that there shall come in the last days scoffers, walking after their own lusts, 4And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation. 5For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water: 6Whereby the world that then was, being overflowed with water, perished: 7But the heavens and the earth, which are now, by the same word are kept in store, reserved to fire against the day of judgment and perdition of ungodly men. (2 Peter 3:3-7)

Principles of Geology was written by Charles Lyell in 1830 espousing the new idea that the great canyons around the world were not the after effects of a world-wide flood (cataclysmic), but the constant erosion over hundreds of thousands of years (uniformitarian; "all things continue as they were from the beginning of the creation"). Until that time, the Bible's description of creation and the cataclysm of Noah's flood were accepted facts. Charles Darwin took a copy of the Lyell's book with him on the S.S. Beagle to the Galapagos Islands, leading to his harmful theories of evolution and the superiority of the white race. Uniformitarianism and evolution eroded people's faith in the historical truth of the Bible. This has led to much false teaching in the church (1 Timothy 6:20) including the pre-tribulation rapture theory, which has led to a lack of holiness, love and power in the church, and a resistance to the truth (2 Timothy 3:1-8).

Deriving the Day of the LORD and the Start of Great Tribulation
Astronomers from the east ascertained the correct year of Christ's first coming, and astronomers from the west (Mayans) have predicted the correct year of Christ's second coming. But the Mayans worshiped the heavens, and so decreed the world's end on the winter solstice of December 21, 2012. God has appointed seven feasts for His people. Jesus fulfilled Unleavened Bread (sinless life), Passover (Lamb that was slain for the sin of the world), First Fruits (He rose from the dead), and Pentecost (He sent His Holy Spirit) during His first coming. The Fall feasts are Trumpets, Day of Atonement, and Booths which Jesus will fulfill during His second coming. September 16th, 2012 is the new moon of Rosh Hashanah, Jewish New Year, the Feast of Trumpets. Trumpets are prominent in the resurrection and rapture and return of Jesus Christ (Psalm 47:5-6; Matthew 24:29-31; 1 Corinthians 15:51-53; 1 Thessalonians 4:14-18; Zephaniah 1:14-18; Joel 2:1-16; Revelation 11:15-19).
John describes the duration of the Great Tribulation as 42 months, 3 1/2 years, and 1,260 days. Counting backwards 1,260 days from September 16th, 2012 brings us to April 6, 2012. Hebrew days begin and end at sunset. Sunset in Jerusalem will be at 7:02 pm that day.

What Event Starts the 3 1/2 Year Clock?
But the court which is without the temple leave out, and measure it not; for it is given to the Gentiles: and the holy city shall they tread under foot forty and two months. And I will give power to my two witnesses, and they shall prophesy a thousand two hundred and three score days, clothed in sackcloth.(Rev. 11:2-3)

Two groups who will be involved throughout the Great Tribulation. The Muslims ("Gentiles") continue to occupy the Temple Mount, so doing so for another 42 months will not seem unusual. The Two Witnesses (Jewish and Gentile believers) are already present and proclaiming the gospel, though not to the point of withholding rain or praying plagues upon our enemies to demonstrate God's power. Counting backwards 1,260 days from September 16, 2012, the Great Tribulation clock begins on April 6, 2009.
All Great Tribulation days and times are according to Hebrew days and Jerusalem time. Dusk in Jerusalem on April 6, 2009, the first day of the Great Tribulation, might not have anything occur physically at all, or it may be very apparent. The war between Israel and Iran might see a major attack. China could stop buying US bonds. Any number of global "natural" disasters could hit.
God starts the Great Tribulation clock. It may be when He tells Michael to release Satan, and Satan "knows that his time is short". Satan's possession of the Antichrist and his deity declaration ("abomination of desolation") may follow shortly thereafter. It may be when God tells the four angels to start sealing the 144,000 (which must occur prior to the first trumpet), or when he tells an angel to announce the everlasting gospel with a loud voice to the world (Rev. 14:6-7).
The more important question is whether your faith can endure until Christ's coming. Jesus has waited to get His Bride for two thousand years. King Jesus is worth waiting for.
For a booklet describing the timing of the events in the Great Tribulation, go to http://www.lulu.com/content/paperback-book/seals-trumpets-and-vials/6668840.