Thanks Jeffrey - it's certainly highlighted some hidden pockets of orphaned messages for me. I'm going to track this in a separate thread, but basically it seems there's a few edge cases where ACKs are being saved and don't end up in the IO log and don't get an entry in the Message Header table.

Based on this, is it fair to assume that the following alteration to the SQL query in Scott's above post would give a truer reflection of orphaned messages?

SELECT HL7.ID,HL7.DocType,HL7.Envelope,HL7.Identifier,HL7.MessageTypeCategory,HL7.Name,HL7.OriginalDocId,HL7.ParentId, HL7.TimeCreated
FROM EnsLib_HL7.Message HL7
LEFT JOIN Ens.MessageHeader hdr
ON HL7.Id=hdr.MessageBodyId
LEFT JOIN Ens_Util.IOLogObj ack
ON HL7.Id = ack.InObjectId
WHERE hdr.MessageBodyId IS NULL AND ack.InObjectId IS NULL

If you're looking to simply convert timezone codes to the UTC offset, I'd setup a simple utility that returns the desired string based on a case statement.

Something like:

ClassMethod DisplayTimezoneToUTCOffset(pInput as %String) As %String{
    Quit $CASE($ZCONVERT(pInput,"U"),
    "CEST":"+02:00",
    "CET":"+01:00",
    "BST":"+01:00",
    :"")
}

If you then want to build the entire string, you could do similar to above for the months, and then have the following:

Class Demo.Utils.ExampleUtils.TimeConvert
{
ClassMethod DisplayDateTimeToLiteral(pInput as %String) As %String{
    // Deconstruct the input string into it's logical parts.
    // Variables starting d are "display" values that will be converted later.
    Set DayOfWeek = $P(pInput," ",1) //Not used
    Set dMonth = $P(pInput," ",2)
    Set Day = $P(pInput," ",3)
    Set Time = $P(pInput," ",4)
    Set dTimeZone = $P(pInput," ",5)
    Set Year = $P(pInput," ",6)

    //Return final timestamp
    Quit Year_"-"_..DisplayMonthToLiteral(dMonth)_"-"_Day_" "_Time_..DisplayTimezoneToUTCOffset(dTimeZone)

}

ClassMethod DisplayTimezoneToUTCOffset(pInput as %String) As %String{

    Quit $CASE($ZCONVERT(pInput,"U"),
    "CEST":"+02:00",
    "CET":"+01:00",
    "BST":"+01:00",
    :"")
}

ClassMethod DisplayMonthToLiteral(pInput as %String) As %String{

    Quit $CASE($ZCONVERT(pInput,"U"),
    "JAN":"01",
    "FEB":"02",
    "MAR":"03",
    //etc. etc.
    "JUL":"07",
    :"")
}

}

Which then gives the following: