Daniel 12:11-12
“And from the time that the daily sacrifice is taken away, and the abomination of desolation is set up, there shall be one thousand two hundred and ninety days. Blessed is he who waits, and comes to the one thousand three hundred and thirty-five days.”

I believe this portion of Daniel is about an event still in the future. I have seen some commentaries declaring the fulfillment before the beginning of the New Testament. However, Jesus said, “Therefore when you see the ‘abomination of desolation,’ spoken of by Daniel the prophet, standing in the holy place” (Matt 24:15), then it’s not possible that it’s fulfilled.
The holy place is a particular section of the Temple, which was in ruins in Daniel’s time and destroyed completely after Jesus’ time.
You can’t have a daily sacrifice or holy place without a Temple, so it seems one needs building in the future.
Now the timeline is interesting – 1290 days and 1335 days.
The Jewish calendar is based on the lunar cycle. Common years can be 353, 354, or 355 days long. Leap years can be 383, 384, or 385 days long.
Daniel’s timeline is around 3-1/2 years but many variables need taking into consideration.
I’m not going into all of that. It’s sufficient to say that something wonderful happens 1335 days after the daily sacrifice ends. The word used is “Blessed is he who waits and comes to the 1335 days.”
If you find this difficult to understand you’re not alone. One lesson to learn is you cannot rush God’s plan.
It’s set in motion like time on a clock. Right at the moment of this writing, it is 4:10 am.
I cannot make it 3 pm. Only letting time and events take place can bring 3 o’clock this afternoon.
Perhaps this is why David said in Psalm 27:14 – Wait on the Lord; Be of good courage and He shall strengthen your heart; Wait, I say, on the Lord!