Pre- or Post-Trib Rapture?

The Rapture of the church involves all believers being caught up to heaven—those just resurrected, together with those alive at the time (1 Thes 4:13-18). If it occurs at the beginning of the tribulation period, then clearly Christ’s Second Coming at the end of the Tribulation to rescue Israel in the midst of Armageddon is a separate event. According to Zechariah 14:3-5, “all the saints” must accompany Christ back to earth. But if the Rapture occurs at the end of the Tribulation, it must be simultaneous with the Second Coming, making them one event. Which is it: two events separated by seven years, or one event with two diverse purposes?