Find last date of a month, given only year and month

[girapas]

In Sheet1 I enter a year and a month. Sheet2 is a database. Column A of Sheet2 filled with working dates. Among other things, I want to find the last date of the year's month entered in Sheet1, and get the cell value addressed of the column G and the same row with that last date.
Thanks in advance

 

[Aladin Akyurek]

Great! Thank you. I hope I'm not be demanding, but there's yet a slight problem. I've named public and local holidays as Holidays2012, Holidays2013 etc. to calculate the working dates. Is there any way to include that dates in the formula you gave me?

The one I proposed would need:

=WORKDAY(DATE(B1,B2+1,1),-1,INDIRECT("Holidays"&B1))

 

[girapas]

Thanks again, both Rick Rothstein and Aladin Akyurek. The fast and effective help you provide, to all "simple excel lovers" like me, is invaluable!
Happy new year.