THe longer the half-life, the less withdrawal. The low end on that figure is more like 18 hours, but if a drug had a reliable 40 hour half-life without actives, I would say there is no withdrawal syndrome for it, without some chronic raging high dose, and even then it wouldn't be a withdrawal syndrome.
If a person hasn't started withdrawal symptoms in like 36 hours, it's not going to happen, because his brain has already adjusted, or been exposed to a condition of no-drug, and nothing bad has happened. It may take longer than that for organs like your bowels to demonstrate that they're operational, but that's only cause you need food and water and transit times.
Will a person feel bad, feel gross, tired, depressed, sure. THat's not a withdrawal syndrome, that's saying goodbye to something you love, plus emotional issues secondary to sleep/food/metabolic disturbances from when a person was on the med, or just from the bucket of Haagen-Daz they put down in one sitting, to help cope with the WD.
If you snap at people, or get more than your usual lack of patience with traffic on the freeway, THAT IS NOT WITHDRAWAL. (I'm not yelling at you Pickles, just the unwashed masses of the forum.) That is to be expected. If it feels like getting yourself to go to the gym after years of not going, and you feel like lead on the eliptical, then we're talking about stopping/starting habits, chemical or otherwise.
There's some research out there showing just how easy it is to convince former benzo dependents that they are going through outrageous withdrawal, when all they got was a shot of saline. So much of it is your brain believing you're trying to give up oxygen, and tricking you into going back for it.
So, let's make clear for OP and other here that 3mg Klonopin is not seizures and exploding legs withdrawal territory. But it's also not good for people with organic brain disease to do stuff with their meds against their doctors' wishes.