Determine the date of the last Sunday in a month

[Grimace]

Good morning all, I hope your XMAS and New Years

I am seeking a formula that will deliver me the date of specific days in the previous month and the following month, given a specific month as input data.

eg If I provide March 2011 as my input data, I need to get the dates of:
- the last Sunday in February 2011
- the first Saturday in April 2011
- the second saturday in April 2011

This will be an ongoing resource, which I will then be copying down indefinitely.
I know I could go through manually and input dates, but where is the fun in that?

In the attached example .. .cells B6 to E6 are what I am looking to auto-populate, given cell A6. and then copy down.

thanks in advance
Darren