Is this where I can ask a Lotus Script question?  I'm new to using Lists, so hopefully this is an easy one.
The below code is a subset what I'm trying to do, but I have narrowed down the error to this  line       If   num <  iMin Then   (if I comment out the if, then there is no error).
I get the Type Mismatch error when I bring up the view that has button on the view.
I tried to do the min as a function (new to Lotusscript functions too), but wasn't sure if that was part of the problem.

Thanks in advance!

        Dim ListOfProgramJoinDates List As NotesDateTime
        Dim LowestDate As NotesDateTime
        
        If  doc.Co_Program1YearJoined1st_DATE(0) = ""   Then
            Set ListOfProgramJoinDates("Program1") =   New NotesDateTime(Datenumber(2400 , 12 , 31))
        Else
            Set ListOfProgramJoinDates("Program1") = New NotesDateTime(Datevalue(doc.Co_Program1YearJoined1st_DATE(0) ))
        End If        

        If  doc.Co_Program2YearJoined1st_DATE(0) = ""   Then
            Set ListOfProgramJoinDates("Program2") =   New NotesDateTime(Datenumber(2400 , 12 , 31))
        Else
            Set ListOfProgramJoinDates("Program2") = New NotesDateTime(Datevalue(doc.Co_Program2YearJoined1st_DATE(0) ))
        End If       
       
        Dim iMin As  New NotesDateTime(Datenumber(2400 , 12 , 31))
        
        Forall num In ListOfProgramJoinDates            
            If   num <  iMin Then '  TYPE MISMATCH ON THIS LINE
'                Set iMin = num                
            End If            
        End Forall
        
        Set LowestDate = iMin
      

I canot comment, let's hope I can modify and add the response ....

You cannot compare two objects using the operator < or >.

Instead you should use a numeric propertiy of both objects like LSLocalTime (if num.LSLocalTime < iMin.LSLocalTime) or use the TimeDifference method of one (if num.TimeDifference(iNum) < 0 then)