I'd say that yes, you should probably switch to a:

(or Start Location + End Location if they differ)

Thus:

• you'll avoid weird cardinality consistence problems (2 ends, or an end without a start)
• in any case, to ensure that a day is concerned by a multi-days event, you have to re-create such a structure at least as an intermediary (via a CTE, a view, subqueries…). So why not having it from the start?