|In the example given all you need to do is change the cell's format to "General". Since, according to Excel, time began in 1/1/1900 = 1 and 9/21/1900 = 265 and 1/21/2013 = 41295.|
Your example will actually equate to 265.7805093. - the .7805 reflecting the time. If you want to get just the day irrespective of the time you can calculate that as =Int(A1) and, again, formt the cell as General.
The question is, why do you need this?