Applying for Tourist Visa without exact dates

Hello,

I'm taking the next year off to travel and would love to be able to include China in my itinerary. Unfortunately, I don't know exactly when I'll be there, or where I'll be staying, since I won't make it until the second half of the year, and won't have it all booked until it gets closer. Any advise on applying? Do I have to apply while I'm in the US (where my passport is from), or could I apply in another country later? Would I have to give up my passport if I was there in person?

Thanks so much!