When you open the workbook and show a greeting message.

[marreco]

Hi.
As I do when I open the workbook and show a message of greeting.

example from 00:00 to 11:59 show "Good Day"

in the case of the 12:00 to 17:59 show "Good afternoon"

in the case of 18:00 to 23:59 show "Good night"

Private Sub Workbook_Open()
Dim T As Date

T = Now

If T >= "0:00" Then
MsgBox "Good Morning"

ElseIf T >= "12:00" Then
MsgBox "Good afternoon"

ElseIf T >= "18:00" Then
MsgBox "Good night"

End If
End Sub