Thought this was an interesting article:

 

http://io9.com/the-real-story-behind-the-1914-christmas-truce-in-world-1674671558

 

 

Very interesting, thanks Klaiber.

 

I was shocked to see 'Xmas' used, I thought it was a modern slang. However, it appears to be as old as the first century but at least as old as the 15th.