Between two dates
With 7/4/2011 in cell A1 and 12/31/2011 in cell B1, I can type this formula in cell C1 to find out that there are 180 days between the 4th of July and New Year’s Eve.
Between date and today
If you always want to find out how many days past due an invoice might be, you could use this function TODAY() in cell E2 subtracting the Invoice Due.
Calculating a future or past date
If you know that a follow-up call will be made to a client in 45 days, you can add 45 to the Last Contact Date in D1 in a formula in E2.
Another great application for date math in Excel is project task tracking. Learn more about this and other project capabilities of Excel kin our latest webinar, Microsoft Excel for Project Management. Click here to register.