My sleep is way off due to my lo getting up almost every 2 to 3 hours if not more, I temp when I know iv gotten the most hours of sleep. He usually wakes up at 1 am and then again at 3 am. I put in the first temp. But I do put the other temp in the notes just for my reference. FF has some great FAQ section!!
Try to get them as close as you can. But just add in the info in notes