We can review the the verses of Chap 11:36-12:4 and note that the first 4 verses of Chap 12 continue the vision that actually started in Chap 10.
Note: If vv. 36–45 continue the description of Antiochus Epiphanes, the account must be viewed as erroneous, since the details do not match what is known of Antiochus’ latter days. Most modern scholars take this view, concluding that this section was written just shortly before the death of Antiochus and that the writer erred on several key points as he tried to predict what would follow the events of his own day. Conservative scholars, however, usually understand the reference to shift at this point to an eschatological figure, viz., the Antichrist. The chronological gap that this would presuppose to be in the narrative is not necessarily a problem, since by all accounts there are many chronological gaps throughout the chapter, as the historical figures intended by such expressions as “king of the north” and “king of the south” repeatedly shift.
Note: The opening phrase of chapter 12, and at that time, makes clear that this passage is talking about the same period of time as the previous context, that is, “the time of the end” (11:40). The action here in verse 1 is not subsequent to the preceding events but coincides with them chronologically.
A. Daniel 12:1-4
I. The "Great" tribulation period. The Angel Michael will come to their aid: See Zech
14 A day of the LORD is about to come when your possessions will be divided as plunder in your midst. 2 For I will gather all the nations against Jerusalem to wage war; the city will be taken, its houses plundered, and the women raped. Then half of the city will go into exile, but the remainder of the people will not be taken away.
3 Then the LORD will go to battle and fight against those nations, just as he fought battles in ancient days. 4 On that day his feet will stand on the Mount of Olives which lies to the east of Jerusalem, and the Mount of Olives will be split in half from east to west, leaving a great valley. Half the mountain will move northward and the other half southward. 5 Then you will escape through my mountain valley, for the mountains will extend to Azal. Indeed, you will flee as you fled from the earthquake in the days of King Uzziah of Judah. Then the LORD my God will come with all his holy ones with him. 6 On that day there will be no light - the sources of light in the heavens will congeal. 7 It will happen in one day (a day known to the LORD); not in the day or the night, but in the evening there will be light. 8 Moreover, on that day living waters will flow out from Jerusalem, half of them to the eastern sea and half of them to the western sea; it will happen both in summer and in winter.
9 The LORD will then be king over all the earth. In that day the LORD will be seen as one with a single name. 10 All the land will change and become like the Arabah from Geba to Rimmon, south of Jerusalem; and Jerusalem will be raised up and will stay in its own place from the Benjamin Gate to the site of the First Gate and on to the Corner Gate, and from the Tower of Hananel to the royal winepresses. 11 And people will settle there, and there will no longer be the threat of divine extermination - Jerusalem will dwell in security.
II. A huge important note here is that this is the only Old testament reference to a "final" resurrection. Verse 2 (Rev 20:4) and a different version of "hell" everlasting contempt. This is the only undisputed reference to this event. It is the most clear and written at least in the 2nd century BC(disputed).
III. The Seal and the End.
A. Let it be understood by those in the time of the end. Enough said.
B. Time, Times and 1/2 Time?
A time, times, and half a time (cf. Dan. 12:7; Rev. 12:14) refer to the three and one-half years of the Great Tribulation, with “a time” meaning one year, “times” two years, and “half a time” six months. This equals the 1,260 days in Revelation 12:6 and the 42 months in Revelation 11:2; 13:5. (Cf. comments on “times” in Dan. 4:16.)
C. 12:11 refer back to 9:27(seventy weeks) I can not explain the 30 days difference. It will be open for discussion.
The angel said that 1,290 days will be measured off from the time that the daily sacrifice is abolished (cf. 9:27, “he will put an end to sacrifice”) and the abomination that causes desolation is set up (cf. 9:27, “one who causes desolation will place abominations on a wing of the temple”). The last half of the 70th “seven” of years is “a time, times, and half a time” (7:25; Rev. 12:14), which is three and one-half years. It is also designated as 42 months (Rev. 11:2) or 1,260 days (Rev. 11:3). How then can the variance of 30 days (1,290 compared with 1,260) be explained? Some suggest that the 30 days will extend beyond the end of the Tribulation, allowing for the judgment of Israel and the judgment of the nations. Another possibility is that the 1,290 days will begin 30 days before the middle of the 70th “seven” of years when the world ruler will set up “the abomination that causes desolation” (Matt. 24:15). The 1,290 days could begin with an announcement (about the abomination) made 30 days before the abomination is introduced. This abomination, as stated earlier, will be an image of himself (Rev. 13:14-15) and will be the symbol of this religious system.
D. Dan 12:13
A. An additional 45 days?
Blessing is pronounced on one who waits for and lives to see the end of the 1,335 days. This is an additional 45 days beyond the 1,290 days (v. 11). Forty-five days after the end of the Tribulation Israel’s long-awaited blessings will be realized. This may mark the blessing of the Millennium; or it may be when Christ, who will have appeared in the heavens (Matt. 24:30) 45 days earlier, will actually descend to the earth, His feet touching down on the Mount of Olives (cf. Acts 1:11). For believers Christ’s coming is a blessing and a glorious hope.