1. Edit the event registration form in question
  2. Select the Language tab
  3. Select Event Details from the dropdown
  4. Next to Date Format, ensure the format is as follows: {0:dddd} {0:m} {0:yyyy}
  5. Click Save

Other configurations:
Using Friday, September 30, 2016 as an example. 

{0:m} {0:d} {0:y} - 30 September 30/09/2016 September, 2016
{0:d} - 30/09/2016
{0:dddd} - Friday
{0:m} - 30 September
{m} - Friday 30 September
{0:y} - September, 2016
{y} - Friday 30 September
{yy} - Friday 30 September
{0:yy} - 16
{0:yyyy} - 2016
{0:dddd} {0:m} {0:yyyy}: Friday 30 September 2016