Summarizing Quantity Using 2 Separate Date Ranges

Perhaps someone has done something like this before. I am generating a quantity summary report. The quantities have to be summarized in two ways:A quantity for a specified date range, which can fall anywhere within the project duration defined by the user provided UserStartDate and UserEndDate A Quantity to date, defined by the ProjectStartDate till the user defined UserEndDate So if I put all these dates in sequence it would look something like this: ProjectStartDate, UserStartDate, UserEndDate, ProjectEndDate Right now in the code the User specified dates are vStartDate and vEndDate. The source data (list of bid items) is compiled in a UNION query (SqlServer View) and I am querying from this view using a stored procedure from which the data is captured using the code below.

Public Shared Function GETeFieldQuantityData( _
ByVal vProjectNo As String, _
ByVal vStartDate As DateTime, _
ByVal vEndDate As DateTime) _
As IEnumerable
' Dim SqlConnection, SqlCommand, and SqlDataReader
Dim vSqlConn As SqlConnection = New SqlConnection(GetConnString)
Dim vSqlCmd As SqlCommand = New SqlCommand("eFieldReturnQuantitySummary", vSqlConn)
'Dim vDataRdr As SqlDataReader
vSqlConn.Open()
'Construct parameters
vSqlCmd.Parameters.AddWithValue("@StartDate", vStartDate)
vSqlCmd.Parameters.AddWithValue("@EndDate", vEndDate)
vSqlCmd.Parameters.AddWithValue("@ProjectNum", vProjectNo)
vSqlCmd.CommandType = CommandType.StoredProcedure
'Return SqlDataReader Object
Return vSqlCmd.ExecuteReader(CommandBehavior.CloseConnection)
End Function
And the SELECT statement returning data to the form:

Code:

SELECT BidItemDesc As [Bid Item Description], Unit,
SUM(Qty) AS [Tot Qty], COUNT(*) AS Records
FROM dbo.qryQuantityWorkSheet
WHERE ((ProjectNum = @ProjectNum)
AND (ProjDate >= @StartDate)
AND (ProjDate <= @EndDate) )
GROUP BY ProjectNum, BidItemDesc, Unit
ORDER BY BidItemDesc