There are 56.5 weeks between August 1, 2011 and August 31, 2012.
A little over 74 weeks are between 1st March 2011 and 1st August 2012.
There are 26 weeks (and 3 days) between August 2010 to February 1 2011.
As of 6/1/12 there are 9.5 weeks until August 11th, 2012
Including the start and end date in the calculation, there are 30 weeks between the two dates.
Since this is just one year, there are 52 weeks from May 2011 to May 2012.
August
104.4 weeks
There are 26 weeks (and 3 days) between August 2010 to February 1 2011.
52 weeks and one day.
34 weeks and 3 days.
There are a total of 13 weeks and 4 days between May 6 and August 9.
There are 52 weeks in a year so in two years (as stated in the question) there are 104 weeks.