Wikipedia has a very thorough write-up https://en.wikipedia.org/wiki/Daylight_saving_time with 171 sources. What degree of certainty are you looking for? It mentions many examples of business (with emphasis on golf and golfers) who pushed to restore DST for the modern era even after the original energy-saving reasons had become obsolete.
Source? I have seen dozens of explanations for DST. None of them well supported by evidence.