As long as you compensate for your body's water losses, it doesn't make much of a difference whether you start your day off with a glass of water or drink it at any other time of day. Just make sure you stay hydrated by drinking water whenever you feel thirsty.
Drinking water first thing in the morning helps you clean out your colon to help you absorb as many nutrients as you can from the food you eat for the rest of the day. Add more minerals to your water with Sunwarrior Liquid Light. It contains antioxidants and electrolytes to replenish those you lost overnight.