转换一次到另一个时区在IE中不起作用

Question

我正面临一些问题 转换一次到另一个时区它不适用于IE和Safari。

var myDate = new Date('20/02/2014 21:46:36 GMT+07:00');
alert(myDate);
var localtime = myDate.getTime();
var localoffset = myDate.getTimezoneOffset()*60000;
var utc = localtime + localoffset;
var targettime = utc + (3600000 * offset);
var c_time = new Date(targettime);
return c_time;

请帮忙