I thought I had answered. So, some detail I think you want.
Yes Peter is talking about the last days and as my diagram shows it is from Jesus sending His Holy Spirit till the great white throne. And that includes quite a lot.
View attachment 26221
Sorry, but that timeline is very misleading.
Apostle Paul placed the "day of Christ" to be Christ's future "thousand years" reign that begins at His future return on the last day of this present world (see Philippians 1:10; Philippians 2:16; and 2 Thessalonians 2:2).
The first day of Christ's future reign is the first day of the "day of the Lord" and starts on the last day of this present world, because that "day of Christ" is meant as that 'day' of a thousand years per 2 Peter 3:8, which is meant literally.
The 3.5 years of Daniel 7:25 (or
"time and times and the dividing of time"), is equal to the 42 months of the dragon's reign of Revelation 13, and the period the Gentiles tread the holy city per Revelation 11, which all those times are for the coming period of "great tribulation" at the end of this present world.
The only time difference to note with that is what we are told in Revelation 11 & 13, because the 42 months is based on a Lunar timing, but the 1360 days God's two witnesses are to prophesy is given according Solar timing. A solar year is just a little bit longer than a lunar year, some say by about 10 or 11 days.
Here is the timeline for the end that I get from God's Word:
1. the "one week" of Daniel 9:27 is the final 'week' in the Daniel 9 seventy weeks prophecy. It is the 70th week, and is for the very end of this world. It is equal to period of 7 years, just like the previous symbolic 'weeks' in the prophecy are.
2. That final "one week" is divided into 2 parts per that Daniel 9:27 verse. That means 2 periods of 3.5 years each.
3. The 1st 3.5 years period involves the coming of the false Messiah and the Jews in Jerusalem building their 3rd temple, and the old covenant worship started up again, with sacrifices. This must... occur to fulfill the prophecy of the false Messiah later ending those sacrifices and instead placing the "abomination of desolation" in Jerusalem.
4. In the middle of the "one week", the false Messiah will end sacrifices in Jerusalem, and instead place the "abomination of desolation" idol in demanding that all worship him in place of God, or all that is called God, or even all things that are worshiped (this per 2 Thessalonians 2). This period is the latter 3.5 years of the symbolic "one week", and will end with Christ's future return on the last day of this present world.