javascript+php实现根据用户时区显示当地时间的方法

window.onload = function() {
//TODO begin 处理登陆用户时区
//获得登陆用户时区与GMT时区的差值
var exp = new Date();
var gmtHours = -(exp.getTimezoneOffset()/60);
setCookie('customer_timezone',gmtHours,1);
//判断是否为夏令时
date = exp.format('yyyy-MM-dd HH:mm:ss');
if(inDaylightTime(date)){
setCookie('inDaylightTime',1,1);
}
}
//设置Cookie
function setCookie(c_name,value,expiredays){
var exdate=new Date()
exdate.setDate(exdate.getDate()+expiredays)
document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : "; expires="+exdate.toGMTString())
}
//判断时间是东半球还是西半球
function isEastEarthTime(newDate)
{
var dj= newDate.getGMTOffset(false);
if (dj.indexOf("-") == -1){
return true;
} else {
return false;
}
}
//是否是夏令时
function inDaylightTime(date){
var start = new Date(date.getTime());
start.setMonth(0);
start.setDate(1);
start.setHours(0);
start.setMinutes(0);
start.setSeconds(0);
var middle = new Date(start.getTime());
middle.setMonth(6);
// 如果年始和年中时差相同，则认为此国家没有夏令时
if ((middle.getTimezoneOffset() - start.getTimezoneOffset()) == 0)
{
return false;
}
var margin = 0;
if (this.isEastEarthTime(date)) {
margin = middle.getTimezoneOffset();
} else {
margin = start.getTimezoneOffset();
}
if (date.getTimezoneOffset() == margin) {
return true;
}
return false;
}
//DONE end

//24小时内 GMT到本地时间的转换
function gmt_to_local($time = '', $dst = FALSE){
//JavaScript设置Cookie,PHP取值
if (isset($_COOKIE["customer_timezone"])){
$timezone = $_COOKIE["customer_timezone"];
}else{
$timezone = 0;
}
if ($time == ''){
return now();
}
//时间处理
$time += $timezone * 3600;
 
//是否为夏令时
if(isset($_COOKIE["inDaylightTime"]) && $_COOKIE["inDaylightTime"]==1)
{
$dst = TRUE;
}
if ($dst == TRUE){
$time += 3600;
}
return date("H:i",$time);
}