>>>I thought EMPTY(ALLTRIM(mytable.mydatetime)) would work to check for an empty datetime field, but I guess I have to convert it first???
>>>
>>Try comparing the field to { }.
>
>Won't Empty(mytable.mydatetime) work?

EMPTY(mytable.mydatetime) should also work. You don't want the ALLTRIM function. It works on strings and a datetime value is not a string.