@enoughisenough ,the 7 year period is based on Daniel 9:27 that describes the final week, the seven-year tribulation period: “[A ruler](=the Antichrist) will confirm a covenant with many for one ‘seven.’ In the middle of the ‘seven’ he will put an end to sacrifice and offering. And on a wing of the temple he will set up an abomination that causes desolation, until the end that is decreed is poured out on him.” Jesus refers to this passage in Matthew 24:15. The ruler who confirms the covenant and then sets up the abomination is called “the beast” in Revelation 13. According to Daniel 9:27, the beast’s covenant will be for seven years, but in the middle of this week (3 ½ years into the tribulation), the beast will break the covenant, putting a stop to the Jewish sacrifices. Revelation 13 explains that the beast will place an image of himself in the temple and require the world to worship him. Revelation 13:5 says that this will go on for 42 months, which is 3 ½ years (the second half of the tribulation).
This is not a jw teaching but that's what most mainstream Christian escatologists believe today. I hope that helps...