Hi Caroline. Thanks for reaching out, and for posting this. I am seeing the issue on your site and appreciate you sharing the links right off the bat (which all too many users forget to do).
I’m wondering if this has something to do with how the event is configured; when I click into it I see that it is set up as a recurring event (http://d.pr/i/m9rP) but recurs only the 1 time. It seems if I understand your goal here, this would make more sense as a standalone two-day event that DOESN’T recur.
Can you try setting it up that way (just disabling the recurrence) and let me know if the issue persists? We can do our best to help address it from there.