I had one further thought in regards as to how the great tribulation is shortened for the elect who are gathered from the four corners of the earth in Matthew 24:21-31. Since the 1,260 days can't be shortened for the Two Witnesses nor for the Antichrist's reign nor for Israel who flees into the wilderness for 1,260 days, the days are shortened for the elect by gathering and removing the elect in the four corners of the earth from the earth which happens when the 6th seal is opened in Rev. 6:12-17.  They don't have to go through the 7 trumpets judgments nor through the 7 vials of wrath judgments.  They are the great multitude that came out of great tribulation and are taken to heaven which are seen up in heaven in Rev. 7.  They don't spend all the 1260 days on Earth.