If I understand correctly, it is just the date in Monarch that shows up like this, and not the source data?
If yes just change the data format on the field properties from format general (the default) to short date. As long as your computer is set to north american date formats, the date will show as m/d/yyyy.
Are the setting in Monarch for the date set up the same way as the orginal data? Options, input date format in ver 7. Make sure that the date format on your the input field matches up to the settings.
If they are not, then the date field is coming in as a string & monarch reads it only as a string & when you switch it to date, it "blanks" out. I am wondering if you have a date string inputing as yyyymmdd, but the input parameter is set uo for m/d/y.
If this is not the case, I am at a loss what to suggest. Monarch is usually very date aware and
all types of dates should work. Then only time you get problems is when you have dates like 02/04/04, as the context does not tell you if you have month-day-year, day-month-year or something else.