Questions about the anime~

[tsuyuhime.livejournal.com]

I'm in the process of writing a few CG fics, and I need some help with the timeline.
At series start, what season was it? And at the time of the ZR, what season was it? >_>; I couldn't really tell since the students don't have different uniforms for summer/winter. I don't remember this ever being actually stated in the anime itself, so... if anyone have any guesses, it would be great.
Another thing. What are those knives/short blades that Xingke use called?

Thank you!