If I were getting a masters degree in world history, my thesis would be an attempt to answer this question: Was there even one day in the recorded history of mankind when no one on the planet was at war? I’ve honestly wondered that my entire life.
Of course, you’d have to create a firm definition of war first. For example, America may have tried to call the war in Vietnam a police action, but I’m sure those covered in napalm were pretty convinced they were at war. Perhaps “non-peace” would be a better term.
By that definition, it would be easy to eliminate huge swaths of time. World Wars I and II. Civil wars. Revolutions. Invasions. Pogroms. Genocide. Hostile occupations. Coups d’etat.
After that, you’d be left with a patchwork quilt of time frames, and you’d have to look at each country and/or culture’s individual history. I’d suggest you go with the big and/or influential countries first. America. Russia. China. England. They are the troublemakers. They’d eliminate a bunch of dates on your calendar. (Of course, reconciling the various calendars so that we’re sure we’re discussing the same day would be an additional challenge.)
Then perhaps go to the more tribal areas of the globe. Whenever you create a scenario that is “us” vs. “them”, you are sure to have conflict. Should we count terrorist activity? If people are getting killed, I’d say yes.
I guess my point is, humans in general are a violent species. I want there to be a day that we can all look to and say, “See? We are capable of peace.” Just one day. I need to know that day exists to give us all hope that it’s really achievable.