Javascript：评估UTC和中欧时间之间的差异

Question

我在Firebase云功能中有一个服务器应用程序，其中webhooks从第三方API接收数据。在这些数据中，我有时间用HH表示：mm当地时间（中欧时间）。我需要将它们作为时间戳UTC存储在Firestore中。

我试过这个：

         //Evaluate offset between CET and UTC
        const dAujourdhui = new Date(); //07/03/2019 10:39 (UTC)
        const nHeureUTC = dAujourdhui.getUTCHours(); //10
        const nHeureLocal = dAujourdhui.getHours();  //10
        const timeZoneOffset = nHeureUTC - nHeureLocal //0!

         // Build a timestamp based on today's date and received time
        const currentDateString = dateFormat(dAujourdhui, "yyyy-mm-dd");
        var estimatedDateTimeOfArrival = new Date(`${currentDateString} ${timeReceivedFrom3rdPartyAPI}`);

         // Add offset to hours
        const utcHour = estimatedDateTimeOfArrival.getUTCHours()
        estimatedDateTimeOfArrival.setHours(utcHour + timeZoneOffset)

        // Save to firestore
        ...

如您所见，我无法评估CET和UTC之间的偏移，因为代码是在UTC中设置的服务器中运行的。

关于如何解决它的任何想法？

Answer 1

这是我发现解决问题的解决方案。它基于外部库：'moment-timezone'

        // Example's initial setup
        const dateFormat = require('dateformat')
        const moment = require('moment-timezone');
        const timeReceivedFrom3rdPartyAPI = "14:30" // Format "HH:mm", Paris time

        // Construct Date object with today's date and timeReceivedFrom3rdPartyAPI
        const currentDate = new Date();
        const currentDateString = dateFormat(currentDate, "yyyy-mm-dd");
        const estimatedDateTimeOfArrival = moment.tz(`${currentDateString} ${timeReceivedFrom3rdPartyAPI}`, "Europe/Paris").toDate()

        console.log(estimatedDateTimeOfArrival)
        // 08/03/2018 13:30 UTC
        // Now I have UTC Full Date corresponding to timeReceivedFrom3rdPartyAPI