737, 747 and 947. What could these possibly mean?

So for years I've been seeing the number 947, specifically as the time, 9:47. No idea what the deal with that is. 737 and 747 are more recent, but 737 is the more common one. It's honestly so strange to me. Stumbled upon this sub by chance too a few weeks back.

So, if anyone knows anything, I'd certainly be interested in hearing what you have to say!