Context, Context! The plain answer to this question is made manifest by consideration of the context in which these numbers appear. By contrast, we note that Daniel 8 prophesied of the Persian and Greek eras of Israeli history. The angel interpreted that for us, so no mystery there. And the mean dude of the Dioduchi, Antiochus Epiphanes, a Seleucid, is described with his persecution lasting 2300 days. It was concluded by the Rededication of the Temple by Judas Maccabee, and that day became the Jewish Festival of Lights (John 10:22).
Daniel 11-12 The number of days in this query are set in a prophetic history that covers the entire SECOND TEMPLE ERA of Judaism. It relates the Persian kings...to the conquest of Alexander the Great...to the break-up of that empire into the Diodochi...to the rise of Antiochus Epiphanes and the Maccabees...to the Roman conquest of the East...to Herod the Great...to the final Destruction of Judea by the Roman generals and the Zealots!
Some of the final verses in this vast prophecy are referred to by Jesus in the Olivet Discourse (Dan. 12:1,11; Matt.24:15,21). The interpretation, then, of these number of days must fit into this first century time period (the End of the Second Temple Era).
Abomination of Desolation According to the synoptic section in Luke, the Abomination of Desolation (...that makes desolate) was the Roman Legions (Luke 21:20). And the number of Days that those armies tromped up and down the land of Judea was 1290! Recall that Jesus warned His disciples to flee JUDEA, not just Jerusalem. This devastation was wide-spread with villages being torched in Galilee, Perea, Samaria, and Judea proper, with supply lines cut off from Jerusalem. When the soldiers finally besieged Jerusalem their fate was sealed, literally! All of this time period, with dates, is recorded by ay an eye-witness Jewish general, Flavius Josephus, who had been captured.
The 1335th Day The city of Jerusalem had its three defensive walls breached. The inhabitants were slaughtered. The Temple was burned and torn down just like Jesus said. Everything was trampled down...EXCEPT for a Herodian palace in the Upper City where the last Jews barricaded themselves and refused to surrender. It is estimated that they had plenty of water and food supplies to last for an indeterminant period of time. The walls were so thick the Roman General, Titus, decided to wait it out.
But amazingly, the remaining Zealots opened the gates on the 1335th day of this war! Note the remarks of Josephus's history concerning Titus's surprise:
Now when Titus came into this (upper city), he admired not only some other places of strength in it, but particularly those strong towers which the tyrants in their bad conduct had relinquished; for when he saw their altitude, and the largeness of their several stones, and the exactness of their joints, and also how great was their breadth, and how extensive their length, he expressed himself...'We have certainly had God for our assistant in this war, and it was no other than God who ejected the Jews out of these fortifications; for what could the hands of man or any machine do towards overthrowing these towers?' (Wars, VI,9:1)
Note that if the tyrants had stayed in the fortress, the Roman Legions would have stayed around the territory and continued to massacre the Jewish people. The soldiers had seen the despicable display of gross inhumanity the Zealots committed on each other and innocent people, and they had no mercy for them. But as Jesus said, with the mysterious surrender, the killing would stop:
And except those days be shortened, there would no flesh be saved, but for the elect's sake those days shall be shortened. (Matthew 24:21-22)
Conclusion These days, 1290 and 1335, are seen fulfilled by recorded history. There is no need for guessing or speculation. They fit the time period required by the chapters 11-12...which end with the topic of the Ending of the Jewish Era. It is this same topic that Jesus dealt with in the first half of the Olivet Discourse, which Jesus said was to occur within that generation: 30-70 A.D.
So, NO, these days do not refer to any Great Tribulation at the End of the World. These Days prophesied, were fulfilled, to the day, in the first century! And they are important because they mark the End of the Old Testament economy, and the beginning of the fantastic Kingdom of God! (Hebrews 8:13, Luke 13:35, 16:16; actually the years 30-70 A.D. were transitioning times.)
{And these days are not referring to Antiochus Epiphanes. He is the topic of Daniel 8, and only part of chapter 11. The events of chapter 11 and 12 speak of a continuous history beyond Antiochus. ALSO, many do not see this continuous history because they cannot get a grasp on the imagery found in the verses 1-4 of chapter 12. But one must read as a Jew, not as a Shakespeare from England. E.g. compare John 5:24 and Eph. 2:1 concerning resurrection.}