There are 365 days inclusive between December 25, 2009 and December 25, 2010.
365 days after December 11 2009 is Saturday, December 11, 2010.
120 days from December 2 2009 is Thursday, April 1, 2010.
81 days as of 12/30/2009
Between December 21, 2009 and June 21, 2010 there are 183 days inclusive.
From 29th December 2009 until March 22, 2010 there are 84 days inclusive.
The 9th of December 2009 was 120 days before it. The 6th of August 2010 was 120 days after it.
It's not clear whether you want those two dates included in the count. Tell you what ! Here's a list of all the days in that neighborhood. You should be able to count the ones you're interested in. December 28, 2009 December 29, 2009 December 30, 2009 December 31, 2009 January 1, 2010 January 2, 2010
There are 392 days from 28 November 2009 until Christmas Day 25 December 2010.
From December 28, 2009 until March 21, 2010 there are 83 days inclusive.
Subtracting 331 days from November 19, 2010 gives December 23, 2009.
There is no precise definition of the start of seasons. Different countries adopt different conventions.