--用日期相减时除去星期天,得到日期相减天数 declare @x datetime,@y datetime set @x='2009-7-1' set @y='2009-7-31' set datefirst 1 if datepart(dw,@X)<>7 begin select datediff(day,@x,@y)-datediff(week,@x,@y) end else begin select datediff(day,@x,@y)-datediff(week,@x,@y)-1 end