Thanks for the replies!

After researching a little more I found a link on the TCOYF website that said the adjustment is .1 degree (F) for each 30 minutes- upward if early, down if late. What I did, since I'm def. post-O and it doesn't much matter, is I put the adjusted temp on my chart but made a note of the actual temp. That way if it later proves to be out of line I can just go back and mark it disturbed.
Oh, and that's a standard adjustment- I've never tested myself to see if I differ from average, so that's what I'm going by.