When you change the dates in an Online Registration that has been active you will get the following message:
This message wants to ensure you are, in fact, just extending the dates of your current registration or adjusting any of the date fields of your current, active registration system.
The warning is making sure you aren't using a previous registration system, for instance from last year, and trying to re-open for the current season. If it's a brand new, sparkly clean registration you are trying to create, please use the clone feature after adjusting the date and this will maintain the previous registration with all of the data and allow you to now make your cloned registration active and ready to be turned on.
Select OK if you are just adjusting the dates of your current, active registration.
Select Cancel if you are trying to create a brand new registration system and click Save Changes to a New Registration (Clone) on the bottom left.