My BCT ship date has changed and I haven't received a new date. How long will I have to wait to receive a new ship date?

First thing to remember, your Recruiter wants you to ship.
Second, don't worry about it. Call your Recruiter, leave a message, and if they don't get back to you call the Recruiting Center.
Third, do PT in the mean time and study your tasks and drills. Be ready before you get there.

Have you called your Recruiter to see if they have that updated info? Or, perhaps calling your MEPS?

theorizing about the army is like asking how some stranger you dont know what you ate on your 5th birthday