I mean think about it. The song was released in 1976 , at the time the world had a population of around ~4.1 billion people. This includes babies and people who can’t move for one reason or another.
Not to mention the fact that if it’s sunny somewhere, it is night time on the other half of the world. You really think everybody just stayed up and not a single person went to sleep instead? Doubtful honestly.
I’ll be generous. The majority of the population lived in Asian countries, so ill say the Asian countries had daytime during this “event” so to speak. And let’s say every single Asian person was king fu fighting all at once. That’s a majority of the world.
In conclusion, there is no way that literally everybody was king fu fighting. MOST people were kung fu fighting is an idea I can get behind, but not EVERYBODY.