When I need to display a date variable (which I do quite often), I use an HTML or ASCII merge. There is a default date format: "MMMM dd, yyyy". Every single time I drop in a date variable, I then have to click on it and change the date formatting. How can I change the default date format?
The "Not Found Value" for a string variable can be changed from the Designer at "Edit Tool Preferences" --> "Designer Config" --> "Default Variable Not Found Text". There is nothing about dates, numbers, etc, though.