At this time, property substitutions are string substitutions only.
To insert a date as a property type, you could use the Transform node and insert the code necessary to reformat the date field. Remember to add the "if nothing else" option to your chain of IF conditions -you need to know if you start getting records that don't meet the expected case.
Another option is to string multiple Split nodes together. However, if you have a large dataflow then the Transform node is the better option.
We have a Jira raised to introduce the addition of new Types; LAE-5015.