How long can you leave drinking water in a bottle before you should tip it out and refill it?

Question

If I filled a bottle with tap water in the morning, is it still okay to drink that night?

After how long should you not drink it?

Answer 1

You shouldn't keep refilling it.  It contains all kinds of bacteria that can cause infection.

Answer 2

The duration of a day should be fine.

I thought water was fresh for ages.

Probably at the point it starts to smell a bit and tastes slightly different is when you should re-fill.

Answer 3

A day or two should be fine for most tap water.

So much makes a difference though. Like what is in your tap water to begin with. Exposure to heat and light will alter time lines too.