What is the precise definition of JDE's Julian Date format?

Question

I am writing code to convert from a Gregorian date to a JDE (J.D.Edwards) Julian date.

Note: a JDE Julian date is different from the normal usag

Answer 1

A sample of VBA code to convert back and forth between JDE Julian Date and Gregorian:

Public Const Epoch = 1900
Public Const JDateMultiplier = 1000
Public Const FirstJan = "01/01/"

Public Function Julian2Date(ByVal vDate As Long) As Date

    Dim Year As Long
    Dim Days As Long
    Dim SeedDate As Date

    '   Day Number
    Days = vDate - (Int(vDate / JDateMultiplier) * JDateMultiplier) - 1
    '   Calendar Year
    Year = ((vDate - Days) / JDateMultiplier) + Epoch
    '   First Day of Calendar Year
    SeedDate = CDate(FirstJan + CStr(Year))

    '   Add Number of Days to First Day in Calendar Year
    Julian2Date = DateAdd("d", Days, SeedDate)

End Function

Public Function Date2Julian(ByVal vDate As Date) As Long

    Dim JYear As String
    Dim BeginDate As Date
    Dim JDays As Long

    '   Calendar Year
    JYear = Format(Year(vDate), "0000")
    '   First Day of Calendar Year
    BeginDate = CDate(FirstJan + JYear)
    '   Day Number
    JDays = DateDiff("d", BeginDate, vDate) + 1

    '   Add Number of Days to Year Number
    Date2Julian = ((CLng(JYear) - Epoch) * JDateMultiplier) + JDays

End Function

I have tried to make it as clear and simple as possible, and to this end I have intentionally left out any error trapping. However, you should be able to add the code to a VBA module and call them directly from your own code.

I also include some useful snippets of T-SQL:

Todays Date as JDE Julian Date:

 (datepart(yy,getdate())-1900) * 1000 + datepart(dy, getdate())

Convert JDE Julian Date to Gregorian (DD/MM/YYYY), replace XXXXXX with the column name containing the JDE Julian Date:

convert (varchar, dateadd (day,convert (int, right(XXXXXX,3)) - 1, convert (datetime, ('1/1/' + convert ( varchar, (cast(left(right(XXXXXX+1000000,6),3) as varchar) + 1900))))),103)

If you require a different Gregorian format, replace the 103 value (right at the end) with the applicable value found here: https://msdn.microsoft.com/en-us/library/ms187928.aspx