How to Date Rocks to Months in the Year of the Flood

Doctor snelling has proposed dating rocks to different months in the year of the flood. But he says there must have been a sudden, year-long increase in rate of radioactive decay. If that happened, it would also apply to magma still inside the earth's surface. That means an omnipotent god could do a special miracle and make this happen - but then you're departing from what scientific evidence suggests.