Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
With Timer1
.Interval = 1000 '设定为 1 秒钟
.Start()
End With
End Sub
Private Sub Timer1_Elapsed(ByVal sender As System.Object, ByVal e As System.Timers.ElapsedEventArgs) Handles Timer1.Elapsed
Dim T As Date = Now
Static Alarmed As Boolean = False '设置为静态或者全局变量
Dim Alarm As Boolean = T.Hour = 12 And T.Minute = 30
If Alarm Then
If Not Alarmed Then
'在这里执行你的程序
End If
Else '
If Alarmed Then
Alarmed = False
End If
End If
End Sub