When creating a Single Event you can choose different time intervals to select in the drop down box. To do this please complete the following steps:

  1. Click "Settings" from the Admin menu on the left
  2. Click "General Settings" directly below "Settings"
  3. Click "System" from the top right of the page
  4. Click "Dates" from the options bar across the top
  5. Click into the "Time DD Time Interval" box at the bottom, it will currently show a number, if it's "60" the time slots will show on the hour, if it's "30" it will show every half an hour and so on
  6. Change this to the required time intervals number
  7. Click "Save"