Since 2007 Indiana Sprint Week has started the second Friday of July.

In 2012 and 2013 the Smackdown started on the 4th Thursday of August. This year it started on the 3d Thursday, but the first day of the month was on Friday. If the first day of the month had been one day earlier, the Smackdown this year would also have started on the 4th, rather than the 3rd, Thursday of August.

Looking at the actual dates for the Smackdown, in 2012 the first night was August 23, for 2013 it was August 22, for 2014 it was August 21. The third Thursday in August in 2015 is August 20. I have absolutely no inside information, but I would bet on it starting on August 20 this year.