How Much Longer Do You Need to Wait to Open a Package?

A couple of weeks ago, a somewhat large package was delivered to my house. The address was correct, but the name was not. I wrote return to sender on it and left it out on my porch for the mailman to take back. It's been days now and the mailman refused to take it back. How much longer do I need to wait until I can open the package? Because the not knowing what's inside is killing me.