I have the same problem. We use the German Version of JMP. When I import a table from Microsoft SQL-Server I get a date if the datatype is datetime (well) and when I import the datatime2(7) I get only a string.
Example for datetime (Correct)
In SQL-Server:
Import in JMP:
Query result: 
Example for datetime2 (not recognized as date, only as string)
In SQL-Server:
Import in JMP:
Query result:
How can I get datetime2 is date in JMP?
Thanks