I have to wonder why you're asking this question. Are you taking some sort of urine test and don't want it to be detected?
While I can't give you a definitive answer on how long alcohol stays in your system (Honestly I don't really know anyhow) I can tell you that most blood/urine tests in this country (USA) also test for adultering agents, that is anything you try to do to mask any drug or alcohol in your system. Testing positive for that is as good as testing positive for whatever it is you're trying to cover up at least as far as most companies/courts are concerned in the USA.
alcohol is not detected in urine.......drugs are.Alcohol content in blood is calibrated with a breathalyzer machine and depending on how long you drank for and within a certain time frame it can show up within a 24 hr.period.Alcohol is metabolized in the body in two ways-carbon dioxide......breathing it out of your system when it has gone thru the bloodstream and then the system flushes it in urination.