Google Posts went live a couple weeks ago, which lets businesses with Google My Business listings post content directly into their local box in the search results, in real-time. It works pretty well but it requires businesses to manage yet another location for sharing promotions and marketing material.
Some are asking if there is a way to schedule these Google Posts or automate them with your posts to Twitter, Facebook, LinkedIn and maybe Google+. The answer is no, not yet at least.
I do not believe there is a public API for this yet, there are some legacy features in Google+ - but I don't know if it works.
A Local Search Forums thread has Joy Hawkins saying "There is currently no way to schedule Google Plus posts - not even from within the Google My Business dashboard."
Who knows, maybe Google doesn't want this feature yet because they are cautious about spam and such?
I would be surprised if we don't see a tool come out soon that does this.
Forum discussion at Local Search Forums.