$date appears to be set to the string "date". I usually use a single $Path variable, just seems simpler to set up that way to me.
You might try using the exploration file that you can download from here: Exploring the use of a $Path Variable in Scripts
You can use insert file, with the "by reference" check box selected to insert one of these files into a container field. Then you can examine some calculation fields in this database file to see the actual file path to the file. By comparing the resulting file path to what you are calculating, you may spot some minor difference that keeps it from working for you.