I think to better understand end times prophecy you often have to connect passages,which means going back to the Old Testament. There are probably many places you can find relevant prophecy scriptures but the account of Noah is very significant since Jesus said the end times would be "as in the days(plural) of Noah." There will be a period of time leading up to the main event that begins the great tribulation. Once Noah entered the ark then it all began,and I believe the ark represents that same protection God will provide for His Elect,in what way or means is yet to be seen. But Noah was in the ark for a total of one year and 10 days,and I personally believe that is significant as well given that the time of GREAT tribulation will be shortened from the final 3 1/2 years. Also there was a 150 day period until the waters started to finally recede. Also a 5 month period mentioned in Revelation where those with the "mark" are tormented,probably near the very end of that period.
I guess the main thing to remember is that it may all play out a lot different than we expect,since the book of Daniel doesn't in any way imply that we will know when that first half of the 70th week(7 years) will begin or even that we will be aware once it has. Other than when the Anti-Christ will "confirm the covenant" and then break it in the midst of that period. And by "covenant" it most likely means he will side with Israel over Palestine but this is not necessarily a peace deal,and even could be done in secret. We may not even be aware that the first 3 1/2 years has even begun. But speaking of the "Day of the Lord" remember that a day with the Lord is as 1,000 years and vice-versa. And technically we have been experiencing over 1,000 years of "tribulation" given all the wars and destruction and the Christian martyrs,especially in the 20th century alone. Which in my opinion shoots down those reasons for a pre-trib. Rapture,since no one else has "escaped" there own horrible deaths. But I do believe again we will have God's protection and even if we are killed by these same judgements on the wicked it will be instantaneous by God's mercy on us.
But speaking of that specific "day" that comes as a thief in the night, I think it's stated that way since you couldn't word it as the 1,260 days of the Lord which would lose the meaning of what scripture is trying to teach. And what comes as a "thief" in the night is obviously the beginning of it all since the very final end would not be a surprise at all and even may be expected by those still alive and aware of the prophetic timetable. But anyway just how I see things possibly taking place and sorry for maybe being a bit "wordy" but just had a lot of thoughts I wanted to express at one time.
~DavidB