Retrobyter,
Excellent job of illustrating the futility of discussing the tribulation and timing of events around it.
The Bible doesn't define "Great Tribulation". Therefore, it could be the first 3 1/2, the second 3 1/2, 7,or even 2000 years. Or it could be unrelated to any of those time periods.
How can you even discuss a topic, if you can't even agree on its definition?
I would encourage everyone to NOT listen to their Pastors on this issue, because they are usually parroting what they've learned in seminary
Address this topic by prayerfully approaching God's word and relying on the revelation of the Holy Spirit. (Rather on the traditions of man)