First, choose your event from the "My Events" page.

Then, go to Event Details under the Setup heading.

Here, you can update the event name, event date, or other event details as needed.

Next, go to Registration under the Setup heading.

If you are using Simple registration or RSVP registration, scroll down to check the Registration end date.

If you are using Ticketed registration or Multi-Event registration, click on the Tickets / Subevents tab and check the Registration close date under each Ticket or Subevent.

Then, go to Website under the Setup heading. Then, click the Edit Website button. Check for any text fields that have the old date or details that need to be updated.