>It will not break, but it will give you a millisecond here and there.
>With ldCount=ldCount+1, you always get about up to 499 milliseconds, and the moment it errors out is when it reaches the 500 - at 501, it breaks the index.

Thanks for the code snippet...here's another one

lnTraps = 0
ldCount = {^2001-01-01 12:00:00 AM}
for j=1 to 100000
	prevldCount = ldCount
	ldCount = ldCount + 1
	if (ttoc(prevldCount) = ttoc(ldCount))
		? j,prevldCount,ldCount,;
			(ldCount - ctot(ttoc(prevldCount))-1+0.00000)
		? "Mod: ",mod(ldCount - ldStart,1)+0.00000 && turns out to be
                                        && 1+calculation from previous line
		lnTraps = lnTraps + 1
	endif
endfor
? lnTraps

This gets one hit, at iteration 92,186 (at 500.02ms error). When stored to the table, the duplicates occur between record 92,000 and 92,184. Maybe the data changes slightly when it gets written to (and/or read back from) the table.

Thanks for playing with me. :)