A Google My Business Help thread has a business complaining that their store hours are not coming up in the Google local listing profile.
Later on, Google said they fixed the issue. Supposedly, some business categories did not show business hours, so Google decided to change it to show it for this business category.
Helmut Geissler, a Google top contributor wrote in the thread:
There are some issues for certain kind of business categories regarding the displayed opening hours and google is aware it and working but on normalizing the kind of dealing with hours.
Later on, Google's Marissa Nordahl explained:
Basically the issue is that the hours are displaying at all - since your category is Import Export Company, we don't display store hours on Maps or Search. It looks like you were able to see the hours on Maps and that is incorrect. We are currently working to normalize this and you shouldn't see store hours for your location on either Maps nor Search soon.
Interesting, don't you think?
Forum discussion at Google My Business Help.