regarding farms like

 https://www.cloudhashing.com/frequently-asked-questions
  "A1: (...) We are currently mining and by September 2013, will be operating at over 115 terahashes. This number will climb steeply to 300 terahashes by November 2013. "
  "A2: We expect mining for September contracts to start by 26th September 2013 (...)"
 
beside that..the date might be a hint for us regarding day1..?

edit:
actually it's not a farm I guess, since they offer their hashrate to customers..mining as a service