Revelation 20: John sees an era he calls 'the thousand years'. After this he sees the resurrection of the dead for judgment. Those not in the book of life are condemned to the lake of fire. After this he sees a new heavens and a new earth.
2 Peter 3: When discussing the coming of Jesus, the author frames the coming as a 'day of judgment' and 'destruction of the ungodly'. To explain the apparent delay of Jesus' coming, he paraphrases one of the psalms, saying that 'one day is as a thousand years, and a thousand years as one day'. The day of the Lord will come suddenly, and then there will be a new heavens and new earth.
Both Revelation 20 and 2 Peter 3 have: references to 'a thousand years', judgment, condemnation of the wicked, and the creation of the new heavens and new earth.
This, to me, suggests that these elements were part of a common set of language and ideas when discussing the Last Day (i.e. that scene in Revelation 20.11-15); otherwise there are just too many parallels for this to be a 'coincidence'. So if we are supposedly using 'scripture to interpret scripture', 2 Peter 3 should be used to help interpret Revelation 20, precisely because of the high parallels between the two of them.
First, 2 Peter 3 is obviously not applying a hard-and-fast rule that God alternates between two modes of temporal perception: that one thousand years is literally perceived by God to be a twenty-four-hour period of time, nor that one day is literally perceived by God to be an eight-million-seven-hundred-sixty-thousand-hour period of time. This is clearly just a poetic analogy, drawn from Psalm 90 (and 2 Peter's use of this psalm goes beyond merely this 'time' aspect). Bringing this to Revelation 20, this would point toward a non-literal reading of the 'thousand years' (amillennial).
Second, 2 Peter 3 has whole context as the apparent delay of Jesus' coming, the day of judgment and destruction and renewal of the heavens and earth. The latter two, in the Revelation, are explicitly postmillennial. But within 2 Peter 3, the coming of Jesus is also postmillennial. His argument is that while the delay between now and then Lord's coming may be even a thousand years, it is merely as a day in his eyes. The author is explicitly using the 'thousand years' concept to explain the present time, with Jesus' coming taking place after the thousand years (postmillennial).
To summarize: 2 Peter 3 has several obvious parallels with Revelation 20, so 2 Peter 3 should be used to help us understand Revelation 20. Second Peter 3 is clearly both amillennial and postmillennial. Hence, 2 Peter 3 compels an amillennial / postmillennial reading of Revelation 20: the thousand years is not a literal one-thousand-year time period, and Jesus' coming takes place after the thousand years, coinciding with the resurrection, judgment, and renewal of heaven and earth.