Google 在 JSON-LD 中报告 ISO 8601 错误

问：

这是我第一次尝试为事件创建 JSON-LD 代码片段。

Google 的网站站长工具（网址检查）在事件日期/时间中报告错误：

日期/时间在“startDate”字段中不是 ISO 8601 格式

我的日期是：

"startDate": "2023-09-16T15:30-16:30",

Google 在 https://developers.google.com/search/docs/appearance/structured-data/event 的示例日期为：

"startDate": "2025-07-21T19:00-05:00",

除了实际值之外，我看不出有什么区别，https://json-ld.org/playground/ 也没有显示任何问题。

如果有帮助，完整的代码片段（删除 stackoverflow 认为是垃圾邮件的链接）是：

<script type="application/ld+json">
    {
      "@context": "https://schema.org",
      "@type": "Event",
      "name": "Think Big",
      "startDate": "2023-09-16T15:30-16:30",
      "endDate": "2023-10-21T15:30-16:30",
      "eventStatus": "https://schema.org/EventEventScheduled",
      "eventAttendanceMode": "https://schema.org/OfflineEventAttendanceMode",
      "location": {
        "@type": "Place",
        "name": "Methodist Church",
        "address": {
          "@type": "PostalAddress",
          "streetAddress": "Old Town",
          "addressLocality": "Stratford-Upon-Avon",
          "postalCode": "CV37 6BG",
          "addressRegion": "Warwickshire",
          "addressCountry": "GB"
        }
      },
      "image": [
        "[removed]"
       ],
      "description": "Confidence boosting workshops for the Shyer Child (for ages 8-9)",
      "organizer": {
        "@type": "Organization",
        "name": "The Beehive, Stratford-Upon-Avon",
        "url": "[removed]"
      }
    }
    </script>