property Calendar.FixedCellWidth as Long
Retrieves or sets a value that indicates the cell's width while the AutoSize is false.

TypeDescription
Long A long expression that defines the cell's width while the AutoSize property is False.

Use the AutoSize, FixedCellHeight and FixedCellWidth properties to defines the size of the control's cell. A cell displays a date. The FixedCellHeight and FixedCellWidth properties has effect only if the AutoSize is False. 

The following sample fixes the cell's size: 

Private Sub Form_Load()
    With Calendar1
        .AutoSize = False
        .FixedCellHeight = 18
        .FixedCellWidth = 32
    End With
End Sub