The following code sets the first and last displayed days to bold. To try the example, place a MonthView control on a form, paste the code into the Declarations section. Run the project and double-click the form.
Private Sub Form_DblClick()
With MonthView1
.DayBold(MonthView1.VisibleDays(1)) = True
.DayBold(MonthView1.VisibleDays(42)) = True
End With
End Sub