Quoting Pistol Amber:" Well the directions on pretty much every test and 99.9% of the doctors I have talked to say FMU your urine is normally at its highest concentration in the mornings. "
Eh, it's debatable. I always got my strong positives with late afternoon urine, personally and there have been some small studies that show a slightly higher amount of women getting positives in late afternoon as opposed to FMU. Remember that nothing is concrete in the world of medicine. Opinions and recommendations can change in the blink of an eye.