In the beginning of your load script, you should see a list of variables that look like this:
SET TimeFormat='h:mm:ss TT';
SET TimestampFormat='M/D/YYYY h:mm:ss[.fff] TT';
It is here where you can set the date format that you want to be recognized, so if you have one that is mostly used, set the date format here and QlikView should always recognize it as a date.
Colin, that is what I was leaning towards and wondered if that would be correct.
Nicole, I am familiar with with initial date setup, it's just from one particular QVD I was loading it was bringing in the InvoiceDate column with two different datatypes. At least it was being read that way. This was in turn breaking my intervalmatch() which is why I wanted a good standard way to FORCE the data to bend to my will.
Thank you both for the quick response.