One cup of coffee contains about 100 milligrams of caffeine which stimulates your mind and helps you remain awake! Coffee keeps you alert & temporarily reduce the need for sleep. Coffee before bed can cause you take more time to fall asleep & you end up having less sleep. Result is you feel sleepy the very next morning. Do you want to remain awake till late night & keep dozing the entire next day? (We guess no is the answer!) So, cut your habit of having coffee before sleep time (sorry coffee lovers!). It will lead to your good sleep at night and happy & productive daytime.