Jersey Mike's Drug Testing?

Hi there. I just want to mention before I start, I don't need to hear any lecturing about how bad smoking weed is. With that out of the way, let us begin. Yesterday, I had a job interview at the sub shop Jersey Mike's. They told me they would call sometime this weekend to set up a second interview if they're still interested in hiring me. At this interview, they told me that they do drug test their employees, and it's the final step to becoming an employee there. Today, I (foolishly) completely forgot about drug testing, and decided to smoke a joint with friends. (It was split between four people.) I very rarely smoke, like once every few months rarely, so I'm not a frequent user by any means. I got called back by Jersey Mike's today and told that I have a second interview on Monday. I don't KNOW if I'm going to be drug tested at this interview, but I want to take precautions just in case. Can anyone attest to the effectiveness of diluting your urine as to make the THC content fall below detectable levels? I'm currently trying to drink a lot of cranberry juice, as it's a diuretic and makes you pee more often. Do you think this will work? (Any useful tips would be great). Also, can anyone who's worked at Jersey Mike's attest to when they do their drug tests? Thanks a bunch for reading and (hopefully) responding.