Hi,
I've successfully loaded into cockpits timestamp values (with or without timezone) from PostgreSQL 9.5 using the default JDBC driver postgresql-9.3-1101.jdbc3.jar provided within installer CE, both in tables and charts (on X axis). Please share your system config if you're still experiencing those issues.
About X asis labels, they're very compressed, I'm sure you can play with options at your choice.
Best regards,
Francesco