Daniel 12 contains a very interesting Q&A.
v6 (Question) "How long shall it be to the end of these wonders?"
v7 (Answer) "it shall be for a time, times, and an half;"
If you've been around (Sunday school) for a while that phrase, 'time, times, and an half' would probably sound familiar.
That's because a similar phrase is also found in Daniel 7:25 (a time and times and the dividing of time.) and in Revelation 12:14 (a time, and times, and half a time).
For brevities sake, I will not give an exhaustive explanation here. But that phrase, in all of it's forms, has come to be understood as meaning a three and a half (3.5) year period of time.
Time = 1
Times = 2
Half = .5
Total = 3.5
It's worth your time to revisit the surrounding text of each of those verses.
It is generally understood that these 3.5 years are the amount of time between the abomination of desolation (at the middle of the Tribulation) and the second coming of Christ. In context, I agree. That is a reasonable explanation for the phrase in Daniel 7:25 and in Revelation 12:14. However, in context, it is not a reasonable explanation for the phrase in Daniel 12:7.
When we take a closer look at the question, and the discussion that leads up to the question, we find that a 3.5 year period of time cannot be a reasonable explanation.
The question is certainly soliciting a time-based response. But there are no specific parameters given that even imply the abomination of desolation, the second coming of Christ, or even the Tribulation. In fact, it's asking for the amount of time until the 'end of these wonders'. So, what was the last 'wonder' that was given?
Daniel 12:2-3 contain the last event given.
"And many of them that sleep in the dust of the earth shall awake, some to everlasting life, and some to shame and everlasting contempt. And they that be wise shall shine as the brightness of the firmament; and they that turn many to righteousness as the stars for ever and ever."
There is only one event given in scripture, where the dead are 'awaken' to 'shame and everlasting contempt'. That event is called the 'great white throne judgement' and it's found in Revelation 20:11-15.
It's relevant to note, that the messianic prophecy that began in Genesis 3:15, is finished in Revelation 20:15.
So the question in Daniel 12:6 is actually asking how long it will be until the end of the great white throne judgement.
Thus, the answer cannot be 3.5 years.
If we look at the prophecies from Daniel's time until the 'end of these wonders', we find that there are three large time-based prophecies.
Daniel 9:24-26 is the '70 weeks' prophecy
Hosea 5:15-6:2 is the 'after two-days' prophecy
and Revelation 20:1-10 is the reign of Christ prophecy
Time = the 1,000 year reign of Christ
Times = the 2,000 years from Christ's ascension to the Tribulation
Half = the '70 weeks' prophecy which is 490 years.
There's also a short time between the second coming of Christ and the beginning of His thousand-year reign, and a 'little season' that Satan will be released to deceive the nations.
In conclusion, the answer given in Daniel 12:7, "it shall be for a time, times, and an half;" means 3,500 years.