how long is the tribulation?

the tribulation is the wrath of satan & lasts for 3 1/2 years

Rev 12:12 Therefore rejoice, ye heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.

time, times & dividing of time = 3 1/2 years

Daniel 7:25 And he shall speak great words against the most High, and shall wear out the saints of the most High, and think to change times and laws: and they shall be given into his hand until a time and times and the dividing of time.

time, times & half = 3 1/2 years

Daniel 12:7 And I heard the man clothed in linen, which was upon the waters of the river, when he held up his right hand and his left hand unto heaven, and sware by him that liveth for ever that it shall be for a time, times, and an half; and when he shall have accomplished to scatter the power of the holy people, all these things shall be finished.

Rev. 12:14 And to the woman were given two wings of a great eagle, that she might fly into the wilderness, into her place, where she is nourished for a time, and times, and half a time, from the face of the serpent.

1,290 days = 3 1/2 years

Dan 12:11 And from the time that the daily sacrifice shall be taken away, and the abomination that maketh desolate set up, there shall be a thousand two hundred and ninety days.

1,290 days = 3 1/2 years

Rev. 12:5-6 And she brought forth a man child, who was to rule all nations with a rod of iron: and her child was caught up unto God, and to his throne. And the woman fled into the wilderness, where she hath a place prepared of God, that they should feed her there a thousand two hundred and threescore days.

a short time = 3 1/2 years

Rev 12:12 Therefore rejoice, ye heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.

42 months = 3 1/2 years

Rev. 13:5 And there was given unto him a mouth speaking great things and blasphemies; and power was given unto him to continue forty and two months.