I would say this is most definitely a WWI era photograph, meaning it would be from sometime around 1914-1918. I'm not an expert on military uniforms - though there are a few on this board and I'd be interested to hear what they have to say - but after a little research, I see that this sort of army uniform is WWI era and distinctly different from WWII army uniforms. Additionally, the other man and boy's clothes and hairstyles, as well as the general style and quality of the photograph, all seem to point to this time frame as well.