iNow = Hour(Time)
If iNow < 6 Then
    strMsg="What are you doing here at this hour?"
 ElseIf iNow >=6 AND iNow <=12 Then
    strMsg="Good Morning."
 ElseIf iNow >=13 And iNow <=17 Then
    strMsg="Good Afternoon."
 Else 
    strMsg="Good Evening."
End If

MsgBox strMsg & VbCrLf & "The current time is " &_
 Time,vbOKOnly+vbInformation,"Welcome"