If you are willing to argue that one days notice is reasonable, sure. It might, it might not depending of facts and circumstances. The higher the percentage of NHCs that actually start deferring on that fist payroll in October would probably be in your favor for reasonableness if the IRS questions it. If most folks don't start til much latter and the owner drops in the 402(g) limit from his bonus in December that probably wouldn't be in your favor for a reasonable notice period.