You don’t want a report to include 25h or 23h twice a year just to be able to send it at some distinct local time.

I absolutely want some daily business reports to cover 25 hours on one day of the year and 23 on another, since that's how long a calendar day is in local time in every place that has DST shifts.

Yes, that's exactly what I want. Everything shifts with dst - business processes, people's working hours, ach windows, ...