Ok, so we all depart earth-time at different times, and arrive in God-time at the same time. That God time, would that not be what we would call the 'rapture'? If we all arrive in God time at the moment Christ is returning to gather us ... thus every eye will see it regardless of when they left.
As for when they left ( died ) It could well be that the time they experience between death and Resurrection is experienced in Gods time not universe time..