4tpg : Я бы использовал не SP а UDF :
CREATE TABLE [dbo].[RepDate] (
[D1] [datetime] NULL ,
[D2] [datetime] NULL
) ON [PRIMARY]

go
CREATE FUNCTION fnD1()
RETURNS datetime
AS
begin
declare @A datetime
set @a= (select D1 from [RepDate])
RETURN @a
end

go
CREATE FUNCTION fnD2()
RETURNS datetime
AS
begin
declare @A datetime
set @a= (select top D2 from [RepDate])
RETURN @a
end
GO

Тогда View выглядел бы так :
create view load (napr,prn,prd)
as
select nnapr as napr, 0 as prn,count(*) as prd
from tabl1
where tr_time between dbo.fnD1() and dbo.fnD2()
group by nnapr
union
select nnapr_rc as napr,count(*) as prn,0 as prd
from tabl1
where rc_time between dbo.fnD1() and dbo.fnD2()
group by nnapr_rc

остается только записывать в таблицу RepDate две даты