I hate at admit it, but I 100% agree with Bazza20 on this, I work in an extremely hot climate during summer, and seriously I drink when I am thirsty, more in summer and less in winter, today was -1 to 10 degrees all day and I only had two mugs of coffee, no actual water and I never was thirsty, and still not thirsty, might have a herbal tea before bed.
Your body knows when it needs water, no point sipping water all day and running to the toilet every 5 minutes, the kids around here do it, running around with water bottles all day long its a habit they have for some reason developed and I think they think it's cool somehow.
I actually think/believe that drinking too much water and drinking water when not required puts additional stress on your body as it's constantly flushing out of your system taking minerals with it, it can also cause other health issues.
About 2 liters of water is required per day on average FROM ALL SOURCES, most people get about 1 litre from food per day so really you only need to drink one litre. Obviously Activity level and climate will change this drastically, but this is where thirst comes into it, a good indicator to have a drink.
Here is an interesting read on the topic:
Can you drink too much water? - Health Wellbeing