"Is the new manager coming next month?"
I had that too. Just wondering if there is a reason that it would be incorrect.
I have been taught that, as a general rule, the subject comes before the time in Chinese sentence structure; however, that being said, I have certainly seen many instances within this app which place the time before the subject. Thus, now I'm just as confused as you on the matter.
It depends on which you want to put emphases on. It does go S-T-P-V-O but sometimes the time IS acting as the subject. I don't believe it can work that way in questions or at least, I haven't seen it too often.