<i>&gt;Congratulations you literally just rescheduled the event. </i><p>What does that mean to <i>reschedule</i>?  Run a SQL batch job on the database to shift the UTC times by 1 hour?!?   Which rows?  All of them?  Or the rows for a particular TZ?  (Better make sure that SQL WHERE clause is error free.)  You&#x27;re just recreating the ambiguity problem but from a different direction.<p>The issue you keep missing is the UTC is <i>ambiguous</i> when attempting to store <i>the scheduling intentions</i> of the user.  If the user wants to store a future socially-constructed datetime, storing it purely as UTC will <i>throw away information</i>.