Dim cnn As ADODB.Connection
Dim RS As ADODB.Recordset
Dim sSQL$, sPath$, iCnt&


    sPath = "C:\file.xlsx"
    
    Set cnn = New ADODB.Connection
    cnn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=""" & sPath & """;Extended Properties=""Excel 12.0;HDR=YES"";"
    cnn.Open
    sSQL$ = "SELECT Дата FROM [Customs$E1:E45000] ORDER BY Дата"
    
    Set RS = New ADODB.Recordset
    Set RS.ActiveConnection = cnn
    RS.Open sSQL$, cnn, adOpenStatic, adLockReadOnly

SELECT Value FROM Customs$E1:E45000 a JOIN 
SELECT Дата FROM Recordset ON ... = ...

SELECT '2013-01-01' as DateStart, DATEADD('d', 15, '2013-01-01') as DateEnd 

declare @i as integer
set @i = 7 
--по факту @i будет задаваться как параметр

;with a as
(
SELECT cast('20130101' as datetime) as DateStart, DATEADD(day, @i, cast('20130101' as datetime)) as DateEnd
UNION ALL
SELECT DATEADD(day,@i, a.DateStart), DATEADD(day, @i, a.DateEnd) 
from a WHERE a.DateStart <= cast('20131231' as datetime)
) 
SELECT Datestart, DateEnd FROM a WHERE a.DateStart <= cast('20131231' as datetime)