That is actually part of the guidelines you can read here. Google states..
Changes to hours creates updates on your Business Profile
After you update your hours or reopen your business, customers who visit your Business Profile will find a message that confirms your recent update. The update also creates a post that confirms you made an hours change. This post shows up on the Updates tab of your profile on mobile devices. You can edit the post to give more information about your updated hours. To remove the hours update message and the post, delete the associated post from Google My Business. "
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.