Whats the impact on business reporting of the order date being out 1 day? Some monthly reports would show up orders that shouldn't be there and should be in previous month...thats it though?

From a practical level I'm wondering of the benefit of trying to fix an issue that has left "order date" out by 1 day on just some orders.

EDIT: And to clarify - you have an impossible task getting them back and then converting again because in storing the value to begin with you have lost the time part of the excel format therefore you can't get it back to the value it originally was, you therefore cannot then apply that through the correct conversion to get the value you need...

Run this to see what I mean

Declare @OrderDate varchar(100)

, @Date1 datetime

SELECT '40441.50551' AS OriginalExcelDate

set @OrderDate = '40441.50551'

set @date1 = (select CONVERT(datetime,CONVERT([varchar](10), dateadd(day,-2,convert(decimal,@orderdate)),101),101))

select @date1 AS OriginalSQLValue

-- Retrieved SQL DateTime in Excel format

set @orderdate = (select CONVERT(numeric(18,4), @Date1, 101))

SELECT @OrderDate AS NewExcelValue

select CONVERT([varchar](10), dateadd(day,-2,convert(decimal,substring(@orderdate,1,5))),(101)) AS NewSQLValue