We should always listen to our body when it comes to hunger or thirst.
Drink water when thirsty.
However, its not a good idea to drink lot of water during the meals, as it may dilute the secreted digestive juices and slow down the digestion process. Preferably drink water half an hour after the meal.
Daily need of water can vary based on the amount of physical work one does in a day, weather conditions, the type of food one consumes in a day, etc. Like in summer our need for water goes up as we lose water through sweating. If you are consuming lot of fruits in a day then water requirement goes down.
So it’s a good idea to listen to your body and drink water when thirsty. And there is no magic number for how much water one should drink.