Dave is right. Sell-by dates don't mean much. Smaller cuts of meat, like steaks as opposed to roasts, likely have a shorter life, but it's still longer than the sell-by date in all likelihood. How long this might be is hard to know. It depends on when the meat was packed, how it was packed, and how it has been handled since.
Sell-by dates don't necessarily have a thing to do with safety. They might have to do with spoilage but not necessarily, again, especially for cryo'd beef. Store policy sets the dates. They can be changed and often are, depending on the policy.
Pack dates are the the only dates with law backing them up. The date the meat is packed must be stamped on the packing case - at the packing house - before it is shipped to distribution centers. Any other dates should, imo, be considered arbitrary.