Here's a chart I found on Revelation. Seems to make it the most understandable for those of you into futurist interpretation. Notice the dreadful days coming are not one Tribulation but two main parts: 1) the Tribulation of 2.5 years, and the last year is really the "Day of the Lord" totally 3.5 years, 1260 days etc. They are two separate events. Then Christ comes back. If you take a Preterist stand, then you need not bother looking at the chart -- I already know your position.