>So couldn't I just make this my default value for datetime columns :
>

cNow = Ctot(Ttoc(Datetime()))

>That way when VFP converts it to string the milliseconds zero out before it hits the table.

You'd better stay away from character-date/datetime, Strictdate settings may come to haunt you. To date and back would be faster and safer:

cNow = <b>D</b>toT(Tto<b>D</b>(Datetime()))

Oh, I misread. If you want to omit the milliseconds, there's no need for it. It indexes on whole seconds. Just try to do a seek, and you'll see - you'd actually have to trim the milliseconds from what you search by, not the index expression.