@Tamerlane Oh wow, interesting, I didn't now that. looked it up on wikipedia, you're right. XD
But it's unrelated to that. November 11. (11. 11.) is "pocky day" - I think I read it's because all those 1s look like pocky sticks or something. Would it be good to put a TL note about that there...?
Probably. I thought it was a made-up thing for this manga. In the West, it's called Veteran's Day in the United States and Armistice Day in Europe. It's for remembering those we have both lost and those who have returned from combat, so we have our own stuff we do.