But Peter's words come originally from Psalm 90:4 "A thousand years in your sight are like a day that has just gone by, or like a watch in the night." Note the Psalm does not make a strict equation of 1 Day = 1,000 years, but rather makes the time period indefinite -- 1,000 years might be a full day for God or just a four hour "watch in the night". So God's experience of time is clearly different than ours, and cannot be strictly equated.
We each get to account for what we individually claim the Scripture says and means. Apparently God did not see fit for Peter to add your particular disclaimer on how He marks time.
I don't suggest one is right, the other wrong, or that one corrects the other, only that the Psalm gives us two different methods for measuring "God's time" and both can only correct if "God's time" is indefinite in our terms.
You disagree?