Is niapsan %00mg ER anight time or morning medicine? My bottle just says take 1. I have been on niaspan 500mg for 3 years, and zocor. But I don't know if they are taken together or if niaspan is a day or night medicine, or zocor.?

Niaspan (niacin) . Niaspan (niacin) is best taken in the morning with a low dose 81 mg aspirin. The Aspirin lessens the flushing that accompanies the niaspan (niacin). Zocor is best taken in the evening, when it is 10% more effective due to the body's biorhythm.
Usually nite. Most people take it at night, just to ward off the flushing side effects. A lot of my patients take it at night with their statin (like your zocor) just because it's easy to remember. But, it's more important to remember to take it, so if you can't remember at night, i'd do it in the morning.