My point is though that in the test they can't tell how recently you used, just if its in your system.(Original post by Elipsis)
I'm not sure if there are tests for it to tell if you are under the influence, or if you've just taken it recently. If you smoked pot 20 days ago it wouldn't be effecting you in anyway but it would still come up on the drug screen because they test the fat in your urine.
Also, there aren't any proper guide lines as to how long certain drugs can be in your system before they are regarded as not having any effect. So the only way to deal with drugs is the same way as alcohol - zero tolerance.
...and how to stay positive