CSV and a calendar file
What the download contains.
export downloads a CSV of every day in the selected year: the date, whether both are open, only one is closed, or both are closed, and the reasons on each side. The ICS file contains one all-day event for each common open day, titled “Both open”.
The files are built in the browser from the lists on the page plus any manual dates you added in that visit. Refreshing the page clears manual dates. They are not an account.
Open the CSV in a spreadsheet before you send it. Quoted reason fields may contain semicolons.