Sub ReText()
Dim iSh As Worksheet
Dim iCl As Range
Dim iFrml$
iFrml = "=СЕГОДНЯ()"  'текст Вашей формулы
For Each iSh In Worksheets
    With iSh.UsedRange
        Set iCl = .Find("Информация за указанный период", LookIn:=xlValues)
        If Not iCl Is Nothing Then
            fAdrs = iCl.Address
            Do
                iCl.FormulaLocal = iFrml
                Set iCl = .FindNext(iCl)
                If iCl Is Nothing Then GoTo DoneFinding
            Loop While iCl.Address <> fAdrs
      End If
DoneFinding:
    End With
Next
End Sub