By applying for the job on Saturday, do you mean you are just submitting the application that day or you're actually going for the drug test? if it's the later, you're fucked sorry bro no way around it.
I was surprised by a dug test once when I first got my job. They are normally really slow before you actually take the test (like months), but they called me within weeks. Two weeks before I did the test, I went to see my friend for spring weekend at Fordham in NYC. We got all types of fucked up. Finished a keg, smoked a lot and did a lot of molly. I was getting high at the gym the next week from the THC still stored in my system haha. Any way, fast forward two weeks and I get blind sided by this test that I'm sure Im going to fail.
THC is stored in adipose cells (fat). Avoid as much physical activity as you can the day before and after the test and drink as much water as you can. I was taking animal pak vitamins before and after that weekend, which I'm sure helped clean out my system.
There is a catch with the water though, do not go into the test with completely diluted urine. They will know and you will have to do it again. The reason people take creatine is because it is a naturally found in urine. It is one of the substances used to determine if your urine is too dilute or not. If you drink too much water, the concentration of creatine will be too low. If you take creatine and dilute your urine, you might be able to slip one past them if you have THC in your system. Keyword is might.