Converting from notes date items to RFC-882. Here's the code.

NB: year can be 2 or 4 digits.

The RFC882 standard is here: http://www.w3.org/Protocols/rfc822/

Here is the code:

Function RFC882Date(Byval dateval As Variant) As String
 ' See http://www.notesninjas.com/A555F9/nn.nsf/ByAlias/RFC882dates

On Error Goto ErrHdlr
RFC882Date=""

'if empty return nothing
If Cstr(dateval)="" Then Goto LeaveSub


Dim dow(7) As String
dow(1)="Sun"
dow(2)="Mon"
dow(3)="Tue"
dow(4)="Wed"
dow(5)="Thu"
dow(6)="Fri"
dow(7)="Sat"

Dim mon(12)
mon(1)="Jan"
mon(2)="Feb"
mon(3)="Mar"
mon(4)="Apr"
mon(5)="May"
mon(6)="Jun"
mon(7)="Jul"
mon(8)="Aug"
mon(9)="Sep"
mon(10)="Oct"
mon(11)="Nov"
mon(12)="Dec"

RFC882Date = dow(Weekday(dateval)) & ", " & Day(dateval) & " " & _
mon(Month(dateval)) & " " & Right(Cstr(Year(dateval)),2) & _
" " & Right("0" & Hour(dateval),2) & ":" & Right("0" & Minute(dateval),2)  & _
":" & Right("0" & Second(dateval),2) & " GMT"


LeaveSub:
Exit Function

ErrHdlr:
RFC882Date=""
Resume LeaveSub
End Function

How to use it:

either simply use it with the document's lastModified property:

print "<Last_Modified>" & rfc882date(doc.lastmodified) & "<Last_Modified>"

or for a Notes item that stores a date time value:

dim ni as notesitem

dim ndt as notesdatetime

If doc.HasItem("LastSaved") Then
   Set ni = doc.GetFirstItem("LastSaved")
   Set ndt = ni.DateTimeValue  
   Print "<LAST_SAVED>" & RFC882Date(ndt.lslocaltime) & "</LAST_SAVED>"
End if

Sometimes LSGMTTime instead of lslocaltime gives better results....

If you are storing dates in text values, (oh dear, please don't), you need to convert it to a date time first, there are some helpful tips here:

http://www.notesninjas.com/A555F9/nn.nsf/ByAlias/NotesDateTime

Let me know if there are problems.

Time zone problems

The time zone can cause problems. You can use LSGMTTime instead of lslocaltime or put in a timezone modifier.

One way to sort this out is to put this code before the main :

 Dim session As New NotesSession
Dim inter As NotesInternational
Set inter = session.International

If inter.TimeZone=0 Then
 tzone=""
Elseif (inter.timezone>0) Then
 tzone="-" & Right$("0" & inter.TimeZone,2) & ":00"
Else
 tzone="+" & Right$("0" & -inter.TimeZone,2) & ":00"
End If

and add tzone to the end of the string :

RFC882Date = dow(Weekday(dateval)) & ", " & Day(dateval) & " " & _
mon(Month(dateval)) & " " & Right(Cstr(Year(dateval)),2) & _
" " & Right("0" & Hour(dateval),2) & ":" & Right("0" & Minute(dateval),2)  & _
":" & Right("0" & Second(dateval),2) & " GMT" & tzone