How long does it take from the time you smoke heroin to show up on a drug test?

within six hours, that's what uis written on the drug n med sheet hanging in most porole and probation offices, they are taught that drugs must be processed and can take anywhere upto 6 hours to show up in urine, but is in blood faster of coarse, my advice don't do drugs and ya never need to worry lol, i hav been clean 11 years this Halloween 2011 and it amazes me the stupid crap i did n thought when i was an active user lol its pure insanity lmao!