Hi Nat,
I tend to stop drinking at around 1pm on my weigh in days ( I get weighed at 7pm) I'm not sure if it's recommended but I do it as I feel like it gives the water time to get out of my system, hopefully giving me a more accurate weigh in! I also tend to drink a little bit less than my usual 3-4 litres.
But it's completely up to you, there are ladies in my group who drink right up to the moment they get weighed!
xx