the eleventh hour of the eleventh day of the eleventh month

I do know now where the pop­py ref­er­ence comes from, thanks to you at this web­site, but I still do not know why we observe the 11th hour of the 11th day of the 11th month. Can some­one help? Is it the ori­gins of the phrase “the eleventh hour,” as in, “the last pos­si­ble hour one could have done some­thing to help?” I think it must be.

What I know is that I buy a pop­py, and always have done since liv­ing in Eng­land dur­ing our first sojourn here or dur­ing this, and I wear it, think­ing that I nev­er had a rel­a­tive who sac­ri­ficed a life dur­ing a war, not for cow­ardice (far from it, I’m sure, think­ing of some of my brave and hot­head­ed young ances­tors!) but for birth dates and edu­ca­tion and dis­abil­i­ty… but I do always think of it. Thank you. Not just for the British, but for the Amer­i­cans and every­one else. Thank you, how­ev­er com­pli­cat­ed things after YOU things may become.