Mine is superb, but I rarely sleep so that may be like cheating....I don't know.....I know what time it is at any given time of the day without ever looking at a clock based purely on the fact that I autistically time my tasks.......Even when sleeping, I never over sleep.....Basically because I wake up every hour.
Granted, these sleep apnea tests that I'm taking now are allowing me to sleep sounder, my waking hours are still completely subject to my ability to know what time it is always. I've been up all morning and haven't looked at a clock yet.......Still, I'm never off more than a minute or two.
Does the sun guide you, or are you a slave to your hand held device?