I am almost done with invitations!

One thing I am working on now is the accommodations card. Are you putting the cut off date on that card? I was think about wording it like this, "Please reference the Smith wedding by July 10 to receive the special rate."
What do you think? Put the date on or leave it off? I guess I am afraid out of town guests might not jump on it and then if they did it too late they wouldn't get the reduced rate.