no se exactamente que te pasa

tienes el notes range, si coges el primer valor

Dim dateRange As NotesDateRange

Dim session As New NotesSession

Set dateRange = session.CreateDateRange()

dateRange.Text= "08/18/96 01:36:22 PM - 08/19/96 01:36:22 PM"

Messagebox dateRange.StartDateTime

Messagebox dateRange.EndDateTime