c# DateTime Diff

Thanks mike, instead I did something like this below, your example lead me to the right answer , thanks man you the greatest!!!!!!!

                       TimeSpan plus4 = new TimeSpan(0, 4, 0);
                        TimeSpan minus4 = new TimeSpan(0, -4, 0);

                        EventLogStatusInfoByOperation elTestInfoEntry = null;

                        try
                        {
                            elTestInfoEntry = (from x in ELStatusByOperationList
                                               where (plus4 >= (x.EL_OpTimeStamp - SystemRecord.MDB_OpDateTime) &&
                                               minus4<= (x.EL_OpTimeStamp - SystemRecord.MDB_OpDateTime))
                                               select x).First();
                        }

Ok this is what im really doing, I already have the lists populated into memory from both tables and stored into class.
 

    Dictionary<int, TestStatusReportByOperationRecord> TestStatusByOpRecord = new Dictionary<int, TestStatusReportByOperationRecord>();

            try
            {

                foreach (SysSummaryByOperation SystemRecord in MDBStatusByOperationList)
                {

                    if (!TestStatusByOpRecord.ContainsKey(SystemRecord.MDB_TPC_ID))
                    {
                        TestStatusByOpRecord.Add(SystemRecord.MDB_TPC_ID, new TestStatusReportByOperationRecord());
                    }


                    //Update Record
                    TestStatusReportByOperationRecord testInfoRec = TestStatusByOpRecord[SystemRecord.MDB_TPC_ID];

                    //plus or minus 2minutes via optimestamp     
                  //the next line below is where im trying to compare the datetime via the plus or minus 3minutes in expression, at the moment I just have something in there until I can figure out to
                    // add the plus or minus 3minutes.
                    //d.EL_OpTimeStamp  and SystemRecord.MDB_OpDateTime are already coming from a list, I just want to take the SystemRecord.MDB_OpDateTime and  verify if its  plus or minus
                    // 3mins from  EL_OpTimeStamp, if so then it will jump to the next couple of lines.

                    // I want to do the logic or linq with where you see green.   you can ignore the where statement, but thats where im trying to put in the plus or minus linq
                  
                    OperationList elTestInfoList = ELStatusByOperationList.Where(d => d.EL_datetime== SystemRecord.MDB_DateTime).First();
                    testInfoRec.A = SystemRecord.A;
                    testInfoRec.EL_dateTime= elTestInfoList.EL_datetime;
                    testInfoRec.EL_B = elTestInfoList.B;
                    testInfoRec.EL_C = elTestInfoList.C;
                    testInfoRec.MDB_Datetime = SystemRecord.MDB_OpDateTime;
                   
                }

Not sure exactly what you wanted, but this should match up the items between 2 tables within 3 minutes in LINQ
class Program
{
static void Main(string[] args)
{
var table1 = new List<DateTime> {new DateTime(2010, 10, 5, 12, 0, 0),
new DateTime(2010, 10, 7, 12, 0, 0),
new DateTime(2010, 10, 8, 12, 0, 0)};
var table2 = new List<DateTime> {new DateTime(2010, 10, 5, 12, 2, 0),
new DateTime(2010, 10, 7, 12, 4, 0),
new DateTime(2010, 10, 8, 12, 1, 0)};
var list =
table1.Select(
d1 => table2.Select(d2 => new { date1 = d1, date2 = d2 }).Where(x => (x.date1 + new TimeSpan(0, 3, 0)) > x.date2 && (x.date1 - new TimeSpan(0, 3, 0)) < x.date2)).ToList();
foreach (var item in list)
{
var innerList = item.ToList();
foreach (var date in innerList)
{
Console.Write("{0} {1}", date.date1, date.date2);
}
Console.WriteLine();
}
Console.ReadLine();
}
}

I want to know is SystemRecord.DateTime in range of + or minus 3mins from d.EL_OpTimeStamp