How do I simulate Excel’s Ceiling/Floor Functions in VBA?

CODE

Public Function Ceiling(ByVal X As Double, Optional ByVal Factor As Double = 1) As Double
    ' X is the value you want to round
    ' is the multiple to which you want to round
    Ceiling = (Int(X / Factor) - (X / Factor - Int(X / Factor) > 0)) * Factor
End Function

Public Function Floor(ByVal X As Double, Optional ByVal Factor As Double = 1) As Double
    ' X is the value you want to round
    ' is the multiple to which you want to round
    Floor = Int(X / Factor) * Factor
End Function