Option Explicit

Sub WypelnijDatami()

Dim startDate As Date
Dim endDate As Date
Dim currDate As Date
Dim i As Integer

startDate = Range("B1").Value
endDate = Range("B2").Value

currDate = startDate - 3 'trzy dni wcześniej
i = 1 'wartość do "indeksowania" komórek

Do While (currDate <= endDate)
    Cells(i, 4).Value = currDate
    currDate = currDate + 1
    i = i + 1
Loop

End Sub