Daniel 8: 13 – 14: Then I heard one saint speaking, and another saint said unto that certain saint which spake, How long shall be the vision concerning the daily sacrifice, and the transgression of desolation, to give both the sanctuary and the host to be trodden under foot? And he said unto me, Unto two thousand and three hundred days; then shall the sanctuary be cleansed.
Daniel 9: 24: Seventy weeks are determined upon thy people and upon thy holy city, to finish the transgression, and to make an end of sins, and to make reconciliation for iniquity, and to bring in everlasting righteousness, and to seal up the vision and prophecy, and to anoint the most Holy.
Daniel 12: 11 – 12: 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. Blessed is he that waiteth, and cometh to the thousand three hundred and five and thirty days.
The 2300 days of Daniel 8 are really 2300 evenings and mornings (Daniel 8: 26: And the vision of the evening and the morning which was told is true: wherefore shut thou up the vision; for it shall be for many days.) or 1150 days. The fulfillment of these days happened between the Old Testament and the New Testament, and speaks of Antiochus Epiphanes who was a shadow of the Antichrist. His desecration of the temple and its cleansing by the Maccabees fulfilled these days (an in-depth and complex explanation of these dates is not given here).
The 70 weeks of Daniel 9 began with the reconstruction of Jerusalem and the temple under Ezra and Nehemiah, and reach unto the Tribulation when Moses and Elijah reveal Christ to Israel.
The 1290 days and 1335 days of Daniel 12 reach beyond the Tribulation, into Armageddon, and culminate at the Millennium when Christ sets up His kingdom. The Tribulation is 1260 days or 3.5 years (Revelation 11: 3; Revelation 12: 6). Adding another 30 days gives the timeframe of Armageddon bringing us to 1290 days (1260 + 30 = 1290). Adding another 45 more days brings us to the Millennium (1290 + 45 = 1335).