Hi,

I`ve got a problem with cells format operations under the Function.
There is the code below and after IF I`d like to clear content of active cell and the cell above or change their color to another but it doesn`t work (but for example merging cells works). The question is why ? It works under Sub but not under Function.
Thanks for help in advance

Code:
Option Explicit 

Function Odliczanie2(data1a As String) As String 

Dim data2 As Date 
Dim data1 As Date 
Dim data2godzina As Integer 
Dim data2dzien As Integer 
Dim roznicaSekundy As Long 

data2 = Now() 

If IsDate(data1a) Then 
  data1 = CDate(data1a) 
  roznicaSekundy = DateDiff("s", data2, data1) 
  data2dzien = Int(roznicaSekundy / 86400) 
  data2godzina = Round((roznicaSekundy - (data2dzien * 86400)) / 3600) 
  
  If roznicaSekundy < 0 Then 
    Odliczanie2 = "PO CZASIE !" 
  Else 
    Odliczanie2 = data2dzien & " d " & data2godzina & " godz " 
  End If 
Else 
  Range(ActiveCell, ActiveCell.Offset(-1, 0)).Clear 
                                                             'lub .Interior.ColorIndex = 23 
End If 


End Function
Excell file attached.
For example column "2" cells F12 and F13.