Thanks for bringing this to our attention! We found a small bug with the start/end date calculations that was manifesting itself in this edge case. We’ve patched a fix to your dev calendar, so if you pull from prod the fix should remain intact.
(As a side note, when we begin LiveWhale 3 upgrades later this year, we plan to move everyone who’s been using the -experimental build into the main track to avoid potential code or bug differences based on that. It’s not anything you need to worry about, but just as an FYI. There are a handful of LiveWhale sites using certain beta or pre-release features that we launched using that “experimental” release track, but all those features will be included in LW3 anyways.)