Here is my test setup

{
  "Zone ID": "harbor_2",
  "Actions": [
    {
      "Frequency": "Once",
      "Time Frequency": "0.00:00:05",
      "Use Game Time": true,
      "Run On": "Enter",
      "Commands": [
        {
          "Command": "global.say <color=green> Enter...</color>",
          "Arguments": [],
          "Clientside": false,
          "Chat Command": false
        }]
    },
    {
      "Frequency": "Once",
      "Time Frequency": "0.00:00:05",
      "Use Game Time": true,
      "Run On": "Exit",
      "Commands": [
        {
          "Command": "global.say <color=green> Exit...</color>",
          "Arguments": [],
          "Clientside": false,
          "Chat Command": false
        }]}]}​