Well the 1/2 life of hydrocodone is about 2 hours which means basically that 1/2 of the hydrocodone is metababilzed in that period of time. The rest metabolizes over the next 36 hours. Of course this is always dependent on the persons metabolic rate. Also there is a dependency on how much someone has taken of how long a period.
Why do you ask? Have you recently quit? I see you were tapering but I am not sure what you are asking. W/Ds last 5-7 days but after that you may feel lethargic and unmotivated.