The date/time of an event series can be edited through the Category that these events were added to.​​​​​​

Here's how:
  1. Navigate to School Website.
  2. Select Events > Calendar Events.
  3. Select your category.
  4. Search by event title and/or From/To date.
  5. To the right of the event, click the Recurring icon.
  6. Make the necessary changes and save.

Recurring icon to right of event series