In November of last year, Google posted that the old business hours spreadsheet format will no longer be supported. Well, that officially went through on on August 8, 2016. If you are using the old spreadsheet format, Google will throw up errors and not be abel to update your business hours.
Google added one column for each day of the week's regular hours and have new rules for formatting hours. You can see the new format for the spreadsheet over here and download it from there was well.
Google said in November, "to gain better control over locations’ hours and avoid eventual formatting errors in Google My Business Locations, you should transition to the new spreadsheet format as soon as it’s convenient for you. In the future, the old format will stop being supported."
Now, you have no choice but to adopt the new format.
Forum discussion at Google+.
