I have an attendance report and our policy is based on 20 days to be taken in
a year on a rolling basis.
Example: During the 2005 year employee took the following sick days
June 4 2005, August 19, 2005, October 23 2005

So, for the year 2006 this employee starts with 17 sick days left and on
June 4 one day is added, on August 19 another day is added, etc.
AND when this employees takes a sick day during the year of 2006 it has to
be deducted

Please tell me there is a formula that will calculate the correct total