I was reading through some of the "other" bible texts (apocraphyls (sp?)) and came across an interesting verse regarding the fallen angels:
ENOCH 10:11 . . . And the Lord said unto Michael: 'Go, bind Semjaza and his associates who have united themselves with women so as to have defiled themselves 12 with them in all their uncleanness. And when their sons have slain one another, and they have seen the destruction of their beloved ones, bind them fast for seventy generations in the valleys of the earth, till the day of their judgement and of their consummation, till the judgement that is 13 for ever and ever is consummated. In those days they shall be led off to the abyss of fire: and 14 to the torment and the prison in which they shall be confined for ever. . . .'
The flood was appearently in the year 2348 BCE. It looks as if, according to the scripture, that when they saw there sons killed by the flood they were to be bound for Seventy Generations. Other scriptures in the bible refer to this abyss, appearently other demons fear going to it.
LUKE 8:26 Then they sailed to the country of the Gadarenes, which is opposite Galilee. 27 And when He stepped out on the land, there met Him a certain man from the city who had demons for a long time. And he wore no clothes, nor did he live in a house but in the tombs. 28 When he saw Jesus, he cried out, fell down before Him, and with a loud voice said, "What have I to do with You, Jesus, Son of the Most High God? I beg You, do not torment me!" 29 For He had commanded the unclean spirit to come out of the man. For it had often seized him, and he was kept under guard, bound with chains and shackles; and he broke the bonds and was driven by the demon into the wilderness. 30 Jesus asked him, saying, "What is your name?" And he said, "Legion," because many demons had entered him. 31 And they begged Him that He would not command them to go out into the Abyss. 32 Now a herd of many swine was feeding there on the mountain. So they begged Him that He would permit them to enter them. And He permitted them. 33 Then the demons went out of the man and entered the swine, and the herd ran violently down the steep place into the lake and drowned.
Revelation, speaks of this further by saying:
REVELATION 9:1 The fifth angel sounded his trumpet, and I saw a star that had fallen from the sky to the earth. The star was given the key to the shaft of the Abyss. 2 When he opened the Abyss, smoke rose from it like the smoke from a gigantic furnace. The sun and sky were darkened by the smoke from the Abyss. 3 And out of the smoke locusts came down upon the earth and were given power like that of scorpions of the earth. 4 They were told not to harm the grass of the earth or any plant or tree, but only those people who did not have the seal of God on their foreheads. 5 They were not given power to kill them, but only to torture them for five months. And the agony they suffered was like that of the sting of a scorpion when it strikes a man. 6 During those days men will seek death, but will not find it; they will long to die, but death will elude them. 7 The locusts looked like horses prepared for battle. On their heads they wore something like crowns of gold, and their faces resembled human faces. 8 Their hair was like women's hair, and their teeth were like lions' teeth. 9 They had breastplates like breastplates of iron, and the sound of their wings was like the thundering of many horses and chariots rushing into battle. 10 They had tails and stings like scorpions, and in their tails they had power to torment people for five months.
So it seems the Abyss is opened before Armageddon (Grear Tribulation) with there (demons) activities leading to the final day. If a person knew how long a "generation" was as used in Enoch would it be possible to calculate the "day" when the Abyss is opened in Revelation? I played around with numbers and figure from the flood until now is approximately 4353 years. The bible speaks of a generation as being 70 to 80 years which would put that figure (70 generations * years) anywhere from 4900 - 5600 years from 2348 BCE. However, I am inclined to believe that the generation spoken of in Enoch is different from the one spoken of in Psalms 90:10. If you were to take the time period from the flood until now and divide by 70(generations) you come out to a time span of about 62 years per generation. As I said, I was just playing with numbers but I find the whole idea presented in Enoch and Revelation very interesting.