SIMPLE QUESTION

It is a simple question that has never been asked: when did the Sideways time line begin?

If you look at some sites, the flash sideways intercuts into the Island story line, begin with the Flight of 815 in September, 2004, and last only for about a week. And since the sideways world was alleged created by the Island characters after their deaths (from 2004-2007), there is some evidence that the sideways world was mirroring the Island time space of the middle of September, 2004.

Except, the sideways world characters had detailed, long term lives, such as Jack and his teenage son, which infers a longer "time period" than merely a week. And since Jack was married to Juliet, the sideways realm infers a totally different series of personal events than the reality of the Island realm.

Why are there such major changes? Why did the sideways world characters create new important people if they were merely "waiting" for Jack to die and "awaken" in the church? And if Jack died in 2007, why were some other characters who survived him (Hurley, Ben, Kate) already "awakened" in the sideways world before Jack?

You could look at these ponder points several ways: 1) you could flip the sideways world around as being the "true" event time line and the Island world as the awakening purgatory; 2) you could say the flash forwards and flash backs were also part of the sideways world and not part of the Island characters past (which means we know nothing about the survivors except was they said and did on the Island); or 3) the sideways world was a Ground Hog Day endless loop of September, 2004 until all the characters died and remembered that the sideways world was not real.

None of these possibilities truly answers the main question: when did the sideways world begin? Was it with Christian's death? Was it with Daniel's time skipping death before he was born? Was it when Jacob's brother died?