I can't speak to the interpretation of the law, but in Japan it's not uncommon to see the hours of a bar or restaurant listed as 17:00-25:00 or 12:00-26:00 or something like that.

No idea if it would be used in this context or if the convention goes all the way back to the 40s, though.

On September 8, 2018 7:55:37 AM UTC, Paul Eggert <eggert@cs.ucla.edu> wrote:
Phake Nick wrote:
 Not really. It would mean the Sunday's clock go to 24:59 before jumping to
 00:00 on Sunday. The official time the DST end is "00:00am on the next day
 after the second Saturday of September". So it isn't ending before the day
 change.

Sorry, but that reading doesn't sound plausible to me. I can't imagine a law 
intending to refer to 24:59.9999... on Sunday (i.e., 00:59.9999.... on Monday) 
talking about the transition occurring the day after Saturday. But perhaps 
someone can dig up a newspaper in the affected area that explains things clearly 
to the general populace.