Yes, the documentation states it returns the value found. If it returns a string, then the field must be text regardless if it looks like dates. I didn't mention that because I focused on the idea of coercing what I figured was a string into a date as suggested by using CDate because in the end, you'd have dates. I also figure that some of the date values would get screwed up during that conversion. So I would not wrap CDate in NZ either if the field is text. If the field is date data type, then perhaps a format has been applied, making the sort look weird for dates.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.