使用javascript将日期时间转换为不同的时区

Question

我使用Bing API的InstantAnswer源通过 jQuery.getJSON 检索JSON格式的航班状态信息。这是我接收的一个例子：

if(typeof SearchCompleted == 'function') SearchCompleted({"SearchResponse":{"Version":"2.2","Query":{"SearchTerms":"LA1442"},"InstantAnswer":{
"Results":[{"ContentType":"FlightStatus","Title":"flight status for Lan Airlines 1442","ClickThroughUrl":"http:\/\/www.bing.com\/search?mkt=en-US&q=LA1442&form=SOAPGN","Url":"http:\/\/www.flightstats.com\/go\/FlightStatus\/flightStatusByFlight.do?id=239598315","InstantAnswerSpecificData":{"FlightStatus":{"AirlineCode":"LA","AirlineName":"Lan Airlines","FlightNumber":"1442","FlightName":"LA1442","FlightHistoryId":239598315,"StatusString":"Landed","StatusCode":76,"OnTimeString":"","ScheduledDeparture":"2011-09-22T17:25:00Z","UpdatedDeparture":"2011-09-22T17:15:00Z","ScheduledArrival":"2011-09-22T18:20:00Z","UpdatedArrival":"2011-09-22T18:17:00Z","OriginAirport":{"Code":"GYE","Name":"Guayaquil","TimeZoneOffset":-18000},"DestinationAirport":{"Code":"UIO","Name":"Quito","TimeZoneOffset":-18000},"DepartureGate":"","DepartureTerminal":"","ArrivalGate":"","ArrivalTerminal":"","PreviousSegment":{"FlightHistoryId":239598314,"OriginAirport":"EZE","DestinationAirport":"GYE"},"DataFreshness":1}}}]}}} /* 

与（与时区有关）有问题的信息是：

• 预定出发时间： 2011-09-22T17：25：00Z
• 预定抵达： 2011-09-22T18：20：00Z

问题在于：如果航班已经离开，我需要预测已经行驶过的航程的百分比。

如果计划出发和预定到达字段与计算机当前时区（仅使用客户端脚本）的相同时区一样，那将很容易计算 - 但它们不是。其中一个在厄瓜多尔使用时区（GMT -5），另一个在智利使用时区（GMT -4）。

我的想法是：

1. 将这两个值转换为unix timestamps
2. 将两个时间戳转换为当前计算机的时区
3. 使用这2个时间戳和my computer's current timestamp
计算飞机的行驶百分比

遇到问题的步骤是否。 2 - 有什么想法吗？谢谢！