Including the start and end date in the calculation, there are 17 weeks between the two dates.
There are 4 weeks in January 2011
4 weeks and 2 days.
From the end of April 2013 to the start of January 2014 is 40.3 weeks, approx.
8.6 weeks
39 weeks
A lot
26
A little over 12 weeks from 1st January 2011 until 31st March 2011.
A little over 21 weeks between January 1 2011 and June 1 2011.
52 weeks and 1 day.
11 weeks and 5 days.
8 weeks and 2 days.