The date on your testamur (certificate) is the date of conferral; the date that the University Registrar formally granted your award.
Conferral means you have officially been awarded your qualification and are now recognised as a legal graduate of Swinburne University of Technology. To be conferred, you must have completed all academic and practical requirements of your course.
Once your degree is conferred, you may begin using any academic titles associated with your award, and your graduation status is formally recognised.