Yes, you can. To duplicate a past event, log into your Symposium account, go to My Events, and then select "Events I've Organized". Once you've found the event you would like to duplicate, select the three dots in the righthand corner of the event card, and select "Clone Event". You can then adjust the newly cloned event to your specifications. 

Please note that when you duplicate an event, all customized forms and pages will carry over, but all participants (attendees, presenters, reviewers, judges) and their submissions will not. All participants will need to resubmit any registration, recruitment, or presentation submission forms in order to attend the new event.