It’s similar to capturing future dates in local time including timezone. There’s no guarantee that 1300 london time on 20-Dec-2029 will be 1300UatC, as the U.K. may shift its daylight rules before then.
That depends entirely ok whether the event being reflected is local or global. If its the time of an solar eclipse, for example, then its unaffected by daylight rules - unlike business hours and such. Working with dates/timestamps is a nightmare, but appears simple at first blush.