That's is long term. Have labour laws and piss tests gone the way of the dodo or is a weekend or evening smoker still f-cked if they smoked up two weeks ago?
Saliva test in the afternoon will tell if you have had any in the last few hours.
Now we just need a pot version of Johnny Appleseed and smoke able pot will be found in every ditch from coast to coast, perhaps then hemp will be discovered as being the plant that should be getting all the attention.
Seedless medical pot, hope Monsanto doesn't get wind of it.