It depends on how fast you can fill the bin.  I normally start the burner and stirrators when I have a couple feet in the bin.  I fill the bin about half full the first day and let dry over night.  I then finish filling the bin the next day and leave the burner and stirrators on until the corn is down to about 16% moisture (tested hot), usually sometime the following day. I leave the air and stirrators on until the moisture of the corn is at the desired level.

Make sure you have enough fan capacity to blow through 18 feet of wet corn and burner capacity to maintain 110 degrees at night.  I like to set my burners so they cycle on and off (2 minutes on and 15 seconds off) during the night.

The only time I have ever had any trouble with this system is if the wet corn is 25% or more, then I take three days to fill.