Determine the last day of the month easily using integrated function(Excel XP, 2003, 2007)

            You often need to check the last day of a particular month for due dates and deadlines. You want to automate this determination of the right date in order to avoid any errors caused due to leap years, for example.
           The table function ‘EOMONTH’ helps in calculating the correct date. In the older versions of Excel, you always need to enable this option first. For this, open ‘Tools | Add-ins’, enable the option ‘Analysis Functions’ and confirm the dialog with ‘Ok’.
            The two criteria required for the ‘EOMONTH’ function are a predefined date and a whole-number diff erence in months. For example, in order to determine the last day of the current month, on the current date in case of stock market orders, you can use
=eomonth(today(),0)
             The argument ‘0’ must also be specified if no other month is desired. A due date at the end of February 2012 can be calculated using the formula
=eomonth(date(2012,2,1),0)
              What is practical here is that you don’t need to think whether a year is a leap year. The last day of a month can be calculated even three months after a particular day thanks to the function =eomonth(‘10.1.2010’,3) 
            Here, ‘10.1.2010’ is the reference date, ‘3’ stands for the last day of the fourth month from today