Visual Basic

TextBox1.Text = DateTime.Now().ToString()

Dim currentTime As DateTime = DateTime.Now()
Dim checkTime As New DateTime(currentTime.Year, _
                              currentTime.Month, _
                              currentTime.Day, _
                              10, 0, 0)
If DateTime.Compare(currentTime, checkTime) = 0 Then
    ' The current time is 10:00am today...
Else
    ' The current time is NOT 10:00am today...
End If

Dim PrevCommentCount As Integer
Dim CurrCommentCount As Integer
Dim CWSName As String
Dim PWSName As String

'Sh corresponds to current sheet
Private Sub Workbook_SheetActivate(ByVal Sh As Object)
    CWSName = Sh.Name
    CurrCommentCount = Sh.Comments.Count
End Sub

'Sh corresponds to previous sheet
Private Sub Workbook_SheetDeactivate(ByVal Sh As Object)   
    PWSName = Sh.Name
    PrevCommentCount = Sh.Comments.Count
    
    If PrevCommentCount <> CurrCommentCount And PWSName = CWSName Then
        Call Utils.UpdateCommentForSheet(Sh.Name)
    End If
  
End Sub


Private Sub Workbook_SheetSelectionChange(ByVal Sh As Object, ByVal Target As Range)
    If Sh.Comments.Count <> CurrCommentCount Then
        Call Utils.UpdateCommentForSheet(Sh.Name)
        CurrCommentCount = Sh.Comments.Count
    End If
End Sub

Option Explicit

Dim m_changedComment_Cell As Range
Dim m_changedComment_Text As String

Private Sub Workbook_SheetSelectionChange(ByVal sh As Object, _
                                        ByVal Target As Range)
    '--when the selection is changed, see if a
    '-- comment was added/deleted/modified                                        
    LookForChangedComment
End Sub

Private Sub LookForChangedComment()
    On Error GoTo End_LookForChangedComment
    
    Dim sMessage As String
    If m_changedComment_Text <> m_changedComment_Cell.NoteText Then
        '-- a comment has been changed; do something useful?
        
        sMessage = "Changed Comment Occured" & vbCrLf & _
          "Cell:  " & m_changedComment_Cell.Address & vbCrLf & _
          "Old Value: " & m_changedComment_Text & vbCrLf & _
          "New value: " & m_changedComment_Cell.NoteText
          
        MsgBox sMessage
              
    End If
    
End_LookForChangedComment:
    Set m_changedComment_Cell = ActiveCell
    m_changedComment_Text = m_changedComment_Cell.NoteText
    
End Sub