DECLARE @FirstDay_M DATETIME --本月初日期        SET @FirstDay_M = DATEADD(mm,DATEDIFF(mm,0,@bDate),0);    DECLARE @LastDay_M DATETIME --本月末日期        SET @LastDay_M = DATEADD(dd,-1,DATEADD(mm,1,@FirstDay_M))    DECLARE @FirstDay_MLY DATETIME --去年本月初日期        SET @FirstDay_MLY = DATEADD(mm,DATEDIFF(mm,0,@bDate)-12,0);    DECLARE @LastDay_MLY DATETIME --去年本月末日期        SET @LastDay_MLY = DATEADD(dd,-1,DATEADD(mm,1,@FirstDay_MLY));    DECLARE @FirstDay_Y DATETIME --本年初日期        SET @FirstDay_Y = DATEADD(yy,DATEDIFF(yy,0,@bDate),0);    DECLARE @LastDay_Y DATETIME --本年末日期        SET @LastDay_Y = DATEADD(dd,-1,DATEADD(yy,DATEDIFF(yy,0,@bDate) + 1,0));    DECLARE @FirstDay_LY DATETIME --去年初日期        SET @FirstDay_LY = DATEADD(yy,DATEDIFF(yy,0,@bDate) - 1,0);    DECLARE @LastDay_LY DATETIME --去年末日期        SET @LastDay_LY = DATEADD(dd,-1,DATEADD(yy,DATEDIFF(yy,0,@bDate),0));        DECLARE @bDate_Y DATETIME -- 去年本日        SET @bDate_Y = dateadd(year,-1,@bDate);    DECLARE @DayLastTime DATETIME -- 日期当前的59分59秒        SET @DayLastTime = dateadd(ss,-1,dateadd(dd,1,@bDate));