<%
n = Trim(Request("n"))

If n = "" Then
    n = 0
End If
n = CInt(n)

cd = DateAdd("ww",n , Date())
w = Weekday(cd, 2)
fd = DateAdd("d", 1-w, cd)

For i = 0 To 6
    dt = DateAdd("d", i , fd)
    response.Write fmtDate(dt) & "<br>"
Next

Function fmtDate(dt)
    Dim y, m, d
    y = Year(dt)
    m = "0" & Month(dt)
    d = "0" & Day(dt)
    m = Right(m, 2)
    d = Right(d, 2)
    fmtDate = y & "-" & m & "-" & d
End Function
%>

<input type="button" value="上一周" onclick="location.href='?n=<%=n-1%>'"> <input type="button" value="下一周" onclick="location.href='?n=<%=n+1%>'">

------解决方案--------------------
本周：DateDiff("ww", Now,theDate)=0
上一周：DateDiff("ww", Now,theDate)=-1
下一周：DateDiff("ww", Now,theDate)=1
就这么简单
如果是ACCESS数据库就用：
本周：selsec * from 表 where  DateDiff('ww', Now,时间字段)=0
上一周：selsec * from 表 where  DateDiff('ww', Now,时间字段)=-1
下一周：selsec * from 表 where  DateDiff('ww', Now,时间字段)=1
mssql数据库：
本周：selsec * from 表 where  DateDiff(ww,getdate(),时间字段)=0
上一周：selsec * from 表 where  DateDiff(ww,getdate(),时间字段)=-1
下一周：selsec * from 表 where  DateDiff(ww,getdate(),时间字段)=1