I have a surgery coming up they want me to quit smoking they're going to test my blood for nicotine when do i have to quit in order for nicotine to not show up?

Ten days or more: Cotinine, a metabolite of nicotine is the chemical assayed in blood or urine tests for tobacco use. It may be positive for ten days since last exposure in a heavy user. Now would be a good time to quit for good.

Quit now for health.: “When someone stops using tobacco and nicotine products, it can take more than two weeks for the blood level of cotinine to drop to the level that a non-tobacco user would have and several weeks more for the urine level to decrease to a very low concentration.” REF: http://labtestsonline.org/understanding/analytes/nicotine/tab/test/