Pissed off? Anyway, that's only natural. The best advice I could give you is to lower your expectations or have none at all. Those due dates aren't actual ETA's, I'm pretty sure they're more like a gossip overheard from the translator muttering to himself on his lunch break "Just maybe, I can finish this by mid July," as he went on to sip some coffee and leave the FTL to play some league of legends. Had it been an official translation work the guy would be fired by now. This is volunteer work after all.
I suppose so.