To help people have a tangible amount of water to focus on, there was a push to recommend that the average person drink 8 glasses of water by 8 PM daily. This would mean that you drank at least 64 ounces of water daily.
There is no solid evidence suggesting that this is, in fact, the right amount, but it is probably a good recommendation for a minimum amount. Depending on your lifestyle, body type, diet, age, and more - this will vary.