How about return flight tickets that China consular has requested?

As I applying for multiple-entry China visa and I do have relevant invitation letters from company in China and Government level trade institute, they have information granting for me 1 year visa. But the consulate asked me to provide them return flight booking confirmation and hotel bookings. I do have residence permit paper which I got from local police station in China as I rent a flat there.
But I am a little bit confused about flight booking, what date should I book the ticket? As in general, I do have many things to do there in China and have to get at least a year visa. But the duration of stay each entry is 30 days. Perhaps anyone could advice me what date is the most appropriate? Can I buy like March or April (if entering China end of this month) and explaining that I will travel to Hong Kong each month in section 3.7 in visa form. Or I must buy the ticket any selected date in January? (But this way they will decide to give me 1 month visa). Thanks