Sorry, I got bad news. Deleting a space permanently removes the space and all of its contents, including any calendars and questions linked to that space.
Deleting a space is permanent – it does not go to the trash and cannot be undone.
If you're unsure about deleting a space, create an XML export of the space as a backup before proceeding. You can then restore the space from the XML export file if you need to.
So maybe there is a backup, even if older? I would also ask the Confluence admin.
For the future, here is the info on how to export the space as a backup: