8 weeks and 5 days
There were 13 weeks between October 1 and December 1, 2009.
56 weeks and 3 days
Including the start and end dates in the calculation, there are 11 weeks between the two dates.
9 weeks and 2 days.
11 weeks and 4 days.
About 78 weeks between June 2009 and December 2010.
260 weeks and 6 days.
313 weeks.
3600 weeks and 2 days.
Between January 1 and October 31 there are 39 weeks.
52 weeks.
There are 99 weeks (23 mounths) between February 2009 and December 2010.