>I'm running VFP8 SP1 and VFP7 SP1. Depending on the format passed in, VFP may expect a 'T' in the datetime format. Seems odd to me.
>
>?CTOT('2003-10-21 00:00:00')
>yields an dempty datetime
>
>?CTOT('2003-10-21T00:00:00')
>yields the correct datetime
>
>?CTOT('10/21/2003 00:00:00')
>yields the correct datetime
>
>?CTOT('10/21/2003 00:00:00')
>yields an empty datetime

Adding to what Sergey said, the first will yield the correct date and time if you add ^ as the first character, indicating that it's a strict date time format.