JS将指定的时间戳转为UTC时间

　　Js中获取时间戳可用var dayMiliseconds = parseInt(new Date().valueOf());Js的时间戳单位为毫秒（1s = 1000 ms）,下面是一个将制定的格式转化成UTC时间的函数。

//format the date string from webservice to UTC time;
function toUTCtime(dateStr) {//Date(1381243615503+0530),1381243615503,(1381243615503+0800)
     dateStr += "";var utcPrefix = 0;var offset = 0;var dateFormatString = "yyyy-MM-dd hh:mm:ss";var utcTimeString = "";var totalMiliseconds = 0;var regMatchNums = /\d+/gi;var regSign = /[\+|\-]/gi;var arrNums = dateStr.match(regMatchNums);utcPrefix = parseInt(arrNums[0]);if (arrNums.length > 1) {offset = arrNums[1];offsetHour = offset.substring(0, 2);offsetMin = offset.substring(2, 4);offset = parseInt(offsetHour) * 60 * 60 * 1000 + parseInt(offsetMin) * 60 * 1000;}if(dateStr.lastIndexOf("+")>-1){totalMiliseconds= utcPrefix - offset;} else if (dateStr.lastIndexOf("-") > -1) {totalMiliseconds = utcPrefix + offset;}utcTimeString = new Date(totalMiliseconds).format(dateFormatString);return utcTimeString;}