count days between two dates

For C#:

DateTime d1=DateTime.MinValue;
DateTime d2=DateTime.MaxValue;
TimeSpan span=d2-d1;

For SQL;
The basic interpretation for your third column would be as follows (the "d" tag measures the date difference in days):

DateDiff("d",[DateReceived],[DateClosed])

If you want to add an exception that handles records with no closed date, use this one (optionally, if you just want to look at records where there is a closed date, add "Is Not Null" as the criteria for ClosedDate and use the top expression):

IIf(IsNull([DateClosed]),"Not Closed Message",DateDiff("d",[DateReceived],[DateClosed]))

Good luck,
OI

http://www.w3schools.com/sql/func_datediff.asp[^]

select DateDiff(DAY,'01-Jan-2012','05-Jan-2012')

Example

DateTime dt = DateTime.Parse("01/01/1980");
   DateTime dt1 = DateTime.Parse("05/01/1980");
   TimeSpan sp = dt1 - dt;
   int dayDiffrence = sp.Days;