Required validation on datetime fields in publishing rules failed.

I was trying to make a date field required in a publishing rule.
The following tag doesn't made the field required.
Geoff suspected it is a bug and ask me to file a this report.

<cfproperty ftseq="1"
> ftfieldset="General"
> name="startDate"
> type="date"
> required="yes"
> ftDefaultType="Evaluate"
> ftDefault="now()"
> ftType="datetime"
> ftDateFormatMask="dd mmm yyyy"
> ftTimeFormatMask="hh:mm tt"
> ftToggleOffDateTime="false"
> ftlabel="Start Date"
> ftValidation="required" />