Google Cloud Functions 时区处理指南：理解与最佳实践

{
  "name": "timezone-example-function",
  "version": "1.0.0",
  "description": "A Google Cloud Function to demonstrate timezone conversion.",
  "main": "index.js",
  "dependencies": {
    "date-fns": "^2.x.x",
    "date-fns-tz": "^2.x.x"
  }
}

const { formatInTimeZone } = require('date-fns-tz');
const { parseISO } = require('date-fns');

/**
 * HTTP Cloud Function to demonstrate timezone conversion.
 *
 * @param {object} req Cloud Function request context.
 * @param {object} res Cloud Function response context.
 */
exports.convertTimezone = (req, res) => {
  // 假设我们有一个来自数据库的 UTC 时间字符串
  const utcDateTimeString = '2023-10-27T10:30:00Z'; // 'Z' 表示 UTC
  const utcDate = parseISO(utcDateTimeString);

  // 目标时区
  const targetTimezone = 'Europe/Berlin'; // 示例：柏林时区
  const anotherTimezone = 'America/Los_Angeles'; // 示例：洛杉矶时区

  // 将 UTC 时间格式化为目标时区的时间
  const berlinTime = formatInTimeZone(utcDate, targetTimezone, 'yyyy-MM-dd HH:mm:ss zzz');
  const losAngelesTime = formatInTimeZone(utcDate, anotherTimezone, 'yyyy-MM-dd HH:mm:ss zzz');

  // 获取当前的 GCF 运行时区（仍是 UTC）
  const gcfRuntimeTimezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
  const gcfRuntimeOffset = new Date().getTimezoneOffset(); // 0

  res.status(200).send({
    originalUtc: utcDateTimeString,
    gcfRuntimeTimezone: gcfRuntimeTimezone,
    gcfRuntimeOffsetMinutes: gcfRuntimeOffset,
    berlinTime: berlinTime,
    losAngelesTime: losAngelesTime,
    message: `原始 UTC 时间 ${utcDateTimeString} 已成功转换为 ${targetTimezone} 和 ${anotherTimezone}。`
  });
};

{
  "originalUtc": "2023-10-27T10:30:00Z",
  "gcfRuntimeTimezone": "UTC",
  "gcfRuntimeOffsetMinutes": 0,
  "berlinTime": "2023-10-27 12:30:00 GMT+2",
  "losAngelesTime": "2023-10-27 03:30:00 GMT-7",
  "message": "原始 UTC 时间 2023-10-27T10:30:00Z 已成功转换为 Europe/Berlin 和 America/Los_Angeles。"
}