I also only saw it used in Japan.
Sometimes businesses use it if they are open until late at night.
Maybe they think it would be confusing to write open from 10am to 2am, as 2am would be already the following day.
So they use the 24 hour format and just continue counting after 24 hours until the end of the "business day".

For example open from 10:00 to 26:00 would mean, open from 10am to 2am the next day.
23:00 (11pm), 24:00 (midnight), 25:00 (1am), 26:00 (2am)