UFN_SCHEDULEDATE_GETPREVIOUSDATEINSESSION

                create function dbo.UFN_SCHEDULEDATE_GETPREVIOUSDATEINSESSION
                (
                    @DATE date,
                    @SCHOOLID uniqueidentifier
                )
                returns date
                as
                begin
                    declare @PREVDATE date

                    select top 1 @PREVDATE = DATE 
                    from SCHEDULEDATE 
                    where INSESSION = 1 
                        and DATE < @DATE
                        and SCHOOLID = @SCHOOLID 
                    order by DATE desc

                    return @PREVDATE
                end