There is a Julian Date user function library available on the Business Objects website - http://technicalsupport.businessobjects.com

Edited by hilfy - 06 Jun 2007 at 8:38pm

I don't get it. Your julian dates are different from the standard julian dates? That sounds strange. Secondly, if your julian dates are unique to your company, then it would be tough for someone here to tell you how convert them. I found a thread on ExpertsExchange.com about this but you have to be a member to read the answers. So I copied a couple replies here. I have no idea if this will help you, but it should get you in the right direction.
==============================
This is a really easy formula to write, but I need to know the year for the sample dates you posted.
The number you posted first, is the number of days from a given date.  I need to determine that date to be able to supply you the formula.
So, can you give me the years for the sample date and expected outcome that you supplied?

Number    Expected Outcome
58829      Jan 24
57607      sept 20
58178      apr 14
58034      nov 21

The month and day are useless without the year.
If I get the year, we can then subtract the number of days to get the starting date.
The formula in Crystal would then look like this if the starting date was 1/1/1900

dateadd("d",{table.field},date(1900,1,1)

Alright. I decided to work on it before going to bed. Here is the formula I used to get this working. I convert it to a string and then parse out the parts of each date and convert them to numbers. Then I use the Date and AddDate functions to combine it into a normal date field.

numbervar JulianDate:=107.157;
stringvar DateString;
dateTimevar NewDate;

DateString := ToText(JulianDate,3);
NewDate:=Date (2000+ToNumber(Mid(DateString,2,2)),1 ,1 );
NewDate:=DateAdd("d", ToNumber(Mid(DateString,5, Length(DateString)-4))-1, NewDate);