I personally adhere to such rules:
During the day I drink as much as I want, while focusing on my own feelings, but be sure to drink at least 2 liters a day.
Do not forget that the intake of food additives (powdered protein, geyner, creatine, etc.) increases the water consumption of the body, consider this when you calculate how much water you need during the day.
I drink water every time half an hour before meals and half an hour after meals (and so every time in between meals), and of course before training, during training and after training (necessary).