Earlier quoted context omitted.
It's a hack because it's easier to change the fundamental concept of time than it is to change all of our published schedules. Imagine if businesses, trains, fairies, parks, etc all had summer and winter hours. A simple glitch in the Matrix twice a year is preferable.
Many parks open and close at sunrise and sunset, effectively ensuring that they have different summer and winter hours.
It's too bad that this would be hard to use for anything besides sunrise and sunset, e.g. "breakfast served daily from sunrise+1h to sunrise+6h".