I agree to a large extent with the above post about drinking water at the correct (or appropriate) times that maximises its effectiveness on the human body.
I have learnt that drinking 1-2 glasses of water after waking up in the morning helps activate the internal organs. Usually by then, the body would have felt slightly hydrated after not having drunk water for the past 8-10 hours the previous night, so drinking water first thing in the morning would give the body a much needed hydration, and also give the internal organs a wake-up call to start the usual active functions such as digesting food during breakfast and so on, as I understand it.
I am also learning to drink some water before having a meal (lunch or dinner) to aid digestion of the meal. However, when it comes to night time before going to bed, I think there are mixed views from different sources on whether it is advisable. For me, I prefer to drink only a little amount of water (at the most I glass) by dinnertime around 8 pm, and then I try not to drink water after that, or else I might wake up a few times in the early morning hours to go to washroom.
"Drinking a glass of water or warm milk may help soothe you to sleep, according to Dr. Oz, though water is preferable. However, drinking water right before bed may cause you to wake up to urinate during the night, possibly more than once. This could prevent you from getting enough rest to function optimally the next day. If you find this to be a problem, drink enough water throughout the day up until two hours before bedtime so that you are already well hydrated when it is time to go to bed. Then, drink a full glass of water first thing in the morning."