If tickets have been sold to the program, you must change the on sale period on each event individually:
  1. Go to Tickets > Program Search
  2. Search for your program and select
  3. Go to the Event List Tab
  4. Click into desired program event
  5. Click  "Edit event" on the left under "tasks",
  6. Change the On-Sale information section to your desired dates. 
  7. Click Save

If you have not sold any tickets to this program, it is easier to delete the program and create a new program with the correct on-sale information:
  1. Go to Tickets > Program Search
  2. Search for your program and select
  3. Click "Delete Program" on the left under "Tasks"
  4. Go to Events > Add a new Scheduled program. Click the link for more information on how to add a scheduled program. 
  5. Once the program is created go to the On-Sale tab
  6. Click the double drop down arrows next to your desired Sales Method
  7. Click Edit
  8. Set the On-sale time to your desired date
  9. Click Save
  10. Go to the Event List tab
  11. Add your desired program events. Click the link for more information on how to schedule program events.