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Get Meridian from time in Javascript

I have following time "Mon Jun 22 03:45:24 PDT 2015" how can I get Meridian using Javascript.
I was doing this:
d= Mon Jun 22 03:45:24 PDT 2015;
var hours = d.getHours();
var meridiem = "AM";
if (d.getHours() > 12) {
hours = d.getHours() % 12;
if (hours == 2) {
hours = 12;
}
meridiem = "PM";
}
But its not working in IE 8.

you define
d= Mon Jun 22 03:45:24 PDT 2015;
actually it is nothing in javascript
some browser more intelligent some not, it's up to the browser behaviour
you have to tell javascript like that
function getCurrentTime() {
var currentTime;
// here we can give our date
var currentDate = new Date("Mon Jun 22 03:45:24 PDT 2015");
// OR we can define like that also for current date
// var currentDate = new Date();
var hour = currentDate.getHours();
var meridiem = hour >= 12 ? "PM" : "AM";
currentTime = ((hour + 11) % 12 + 1) + ":" + currentDate.getMinutes() + meridiem;
return currentTime;
}

We can get time in 12 hour format, including the meridian by using the Date.prototype.toLocaleTimeString() method with a US English argument which returns the time in AM/PM. Without the argument 'en-US' date will return the format it deems appropriate for your timezone.
From there we can utilise the slice method to get the last two characters of the timestamp using a negative index:
var d = new Date("Mon Jun 22 03:45:24 PDT 2015")
// US English uses 12-hour time with AM/PM
var timestamp = d.toLocaleTimeString('en-US');
// timestamp → "03:45:24 AM"
var meridian = timestamp.slice(-2);
// meridian → "AM"
One liner for brevity:
var meridian = new Date("Mon Jun 22 03:45:24 PDT 2015").toLocaleTimeString().slice(-2);

According to the documentation for JavaScript Date object here, there is no method for directly getting 12-hour hours and therefore no method for getting am/pm directly from the Date object.
You can get hours (24-hour format) which you can use to get 12-hour hours and am/pm. (You've already done it but I don't understand what you're trying to do in your code.)
This would be one way to do this.
This code is inspired by #tinka.
var d = new Date("Mon Jun 22 03:45:24 PDT 2015");
var h = (d.getHours() + 11) % 12 + 1; //Courtesy #tinka
var m = h > 12 ? 'pm' : 'am';
And you can always add methods to Date.prototype if you're gonna be using them repeatedly.
Date.prototype.getHours12 = function() {
return (this.getHours() + 11) % 12 + 1; // edited.
}
Date.prototype.getMeridiem = function() {
return this.getHours() > 12 ? 'pm' : 'am';
}
It should work on all platforms.

With Date object:
getMeridiem(date: Date) {
return date.toLocaleTimeString().split(' ')[1];
}

Set Date Time to Jquery date time picker

I have date in Javascript
Sun Feb 15 2015 08:02:00 GMT+0200 (EET)
how I can to set in format 'dd/mm/yyyy hh:mm:ss' into datetime picker?
If I set like this:
dateStart
Sun Feb 15 2015 08:02:00 GMT+0200 (EET)
$('#dateTimeStart').datetimepicker('setDate', dateStart);
Error parsing the date/time string: Missing number at position 10
date/time string = 02-15-2015 08:02:00
timeFormat = HH:mm
dateFormat = mm-dd-yyyy

$('#dateTimeStart').datetimepicker({
dateFormat: 'yy-dd-mm'
timeFormat: "hh:mm:ss"
});

You have to format date that you have. You can do it with help of function that you can grab here.
Usage:
<script>
document.write($.format.date("Sun Feb 15 2015 08:02:00", "dd/mm/yyyy hh:mm:ss"));
</script>
It's small and really nice solution that can help you to resolve your issue.

You're looking for a format like
jQuery('#dateTimeStart').datetimepicker({
format:'d/m/Y H:i:s'
});
According to the DateTimePicker documentation at http://xdsoft.net/jqplugins/datetimepicker/, the 'format' string is based on the PHP date format strings, which you can read up on at http://php.net/manual/en/function.date.php. Note in particular they use just one letter to represent multiple numbers (e.g. 'd' instead of 'dd')

use below javascript code to change formate
var date = new Date('Sun Feb 15 2015 08:02:00 GMT+0200');
var day = date.getDate();
var month = date.getMonth();
var year = date.getFullYear();
var hours = date.getHours();
var minutes = "0" + date.getMinutes();
var seconds = "0" + date.getSeconds();
var fulldate = day+'/'+(month+1)+'/'+year+' '+hours + ':' + minutes.substr(minutes.length-2) + ':' + seconds.substr(seconds.length-2);
see working copy of fiddle
you can create function which return date in format
function convertdate(param){
var date = new Date(param);
var day = date.getDate();
var month = date.getMonth();
var year = date.getFullYear();
var hours = date.getHours();
var minutes = "0" + date.getMinutes();
var seconds = "0" + date.getSeconds();
return fulldate = day+'/'+(month+1)+'/'+year+' '+hours + ':' + minutes.substr(minutes.length-2) + ':' + seconds.substr(seconds.length-2);
}
alert(convertdate('Sun Feb 15 2015 08:02:00 GMT+0200'));

I change format of date from server in this : '02/15/2015 08:02:00 AM'
and then I parse this string and create new date:
var dateString ='02/15/2015 08:02:00 AM';
var dateStart = new Date(Date.parse(dateString, "mm/dd/yyyy hh:mm:ss"));
$('#dateTimeStart').datetimepicker('setDate', dateStart);

How to make JS date respect local timezone?

I have the follow function that properly returns the date in the format required, but the value returned isn't respecting the local timezone. In this case, its 4 hours off. What would I need to modify in this function to make it add the proper offsets based on the users location?
Thanks!
function date_str(seconds) {
var dt = new Date(1970, 0, 1);
dt.setSeconds(seconds);
console.log(dt);
var month = dt.getMonth() + 1;
var date = dt.getDate();
var year = dt.getFullYear();
var hours = dt.getHours();
var minutes = dt.getMinutes();
var ampm = hours >= 12 ? 'PM' : 'AM';
hours = hours % 12;
hours = hours ? hours : 12;
minutes = minutes < 10 ? '0' + minutes : minutes;
return month + '/' + date + '/' + year + ', ' + hours + ':' + minutes + ' ' + ampm;
}
Edit: Passing unix time to function 1396450616.505 which converts to Wed, 02 Apr 2014 14:56:56 GMT which returns Sent at 4/2/2014, 2:56 PM from the function itself. The time here is 10:56 AM EST.

Assuming that seconds is a unix epoch (UTC), you should just use
function date_str(seconds) {
var dt = new Date(seconds*1000);
console.log(dt);
…
instead. The get…() methods will respect the local timezone. If you don't want that, you should use the getUTC…() equivalents.

Convert UTC datetime to local datetime

I tried many times to convert utc datetime to local datetime,and I have failed. My utc datetime format is
Fri Mar 8 23:12:27 UTC+0200 2013
Also my JavaScript code is
var time = Date(param_time);//param_time is /Date(1362866006646)/
And then time is being Sun Mar 10 00:21:54 UTC+0200 2013 I need to datetime as 2008-01-28T20:24:17Z because I will convert local datetime to pretty datetime.
http://ejohn.org/files/pretty.js
How can I do this ? I looked at many questions on stackoverflow but no one does it work. Thank you.

In order to format your Date correctly use toISOString():
var time = param_time.toISOString();
Note that param_time needs to be a valid Date object.
References
MDN: Date (sections: Syntax, Example: ISO 8601 formatted dates)

I rarely use javascript and all this date time conversion are mystery to me as well, javascript is a client side technology and all this "UTC" phrases means nothing (at least to me), as all the kind of getUTC...()/setUTC...() functions works in local time, the same is goes for all Date.to...String() functions, even the new Date() (that due to the docs) s'd be initialized in UTC, also give a local time.
However, if you have a (correct) date in UTC and wish to convert it to current (client side) local time, then you need getTimezoneOffset(), or shortly:
function UTCToLocalTime(d) {
var timeOffset = -((new Date()).getTimezoneOffset()/60);
d.setHours(d.getHours() + timeOffset);
return d;
}
var time = new Date(Date.parse('Fri Mar 8 23:12:27 UTC+0200 2013'));
alert(UTCToLocalTime(time)); // Sat Mar 9 01:12:27 UTC+0200 2013
//p.s. or...
function UTCToLocalTime2(d)
{
return new Date(d.toString().replace(/UTC.*/g,"") + d.getYear());
}

var timezone = "UTC+01:30";
var start = new Date();
if(timezone != "UTC"){
timezone = timezone.replace(/UTC/g,"");
znak = timezone.charAt(0);
timezone = timezone.replace(/[+|-]/g,"");
timezone = timezone.split(":");
//var start = new Date(start.toString() + " " + timezone);e.
//alert(start.toString());
if(znak == "+") start = new Date(start.getTime() + (timezone[0]*60*60000 + timezone[1] * 60000) );
if(znak == "-") start = new Date(start.getTime() - (timezone[0]*60*60000 + timezone[1] * 60000) );
}
var hours = start.getUTCHours();
var minutes = start.getUTCMinutes();
var seconds = start.getUTCSeconds();

var day = 10;
var month = 04;
var year = 2015;
var dateUtc = Date.UTC(year, month - 1, day + 1, 0, 0, 0);
> 1428710400000
var toDate = new Date(dateUtc);
> Fri Apr 10 2015 21:00:00 GMT-0300 (Hora oficial do Brasil)

javascript date & time join

I have two date variable separately like following
startDate is a Date instance with the value Tue Jul 17 2012 00:00:00 GMT+0530 (IST)
startTime is a String with the value "11:30 AM"
Now what I need is join of both above date & time, as a Date.
startDateTime = Tue Jul 17 2012 11:30:00 GMT+0530 (IST)
I tried
new Date(startDate + " " + startDate) but outputting invalid date.
Also tried the way shown on this post. But still not working.

You can readily parse startTime if it's in a clearly-defined format, then use setHours and setMinutes: Live example | source
var startDateTime;
var parts = /^(\d+):(\d+) (AM|PM)$/.exec(startTime);
if (parts) {
hours = parseInt(parts[1], 10);
minutes = parseInt(parts[2], 10);
if (parts[3] === "PM" && hours !== 12) {
hours += 12;
}
else if (parts[3] === "AM" && hours === 12) {
hours = 0;
}
if (!isNaN(hours) && !isNaN(minutes)) {
startDateTime = new Date(startDate.getTime());
startDateTime.setHours(hours);
startDateTime.setMinutes(minutes);
}
}
...or something along those lines.
Note that key to this is the fact you've said startDate is a Date instance. The above assumes we're working within the timezone of the JavaScript environment, not across zones. If you were starting with a date string instead, and that string specified a timezone other than the JavaScript environment's timezone, which you were then converting into a Date via new Date("Tues Jul...."), then you'd have to be sure to adjust the resulting Date to use either the local time of the environment, or UTC; if you adjusted it to be UTC, you'd use setUTCHours and setUTCSeconds above instead of setHours and setSeconds. Again, this is only an issue if your starting point is a date string, and that string specifies a timezone different from the timezone in which the code above is running.

You can do This:
var theDate = new Date("Tue Jul 17 2012 00:00:00 GMT+0530 (IST)");
var theTime = "11:30 AM";
var hours = theTime .substr(0,2);
var minutes = theTime .substr(3,2);
var amOrPm = theTime .substr(6,2);
if (hours < 12 && "PM" == amOrPm) {
hours = +hours + 12;
}
theDate.setHours(hours);
theDate.setMinutes(minutes);

Try
new Date(startDate.toDateString() + " " + startTime)
This combines the date string from your Date object with the time string, and should give you a valid date. Note that this ignores the timezone you initially worked with, you might need to add " GMT+0530" again.
However, because your date string is already timezone-biased (Jul 16 2012, 20:30:00 UTC) it might be better to add them together, i.e. like new Date(+startDate + milliseconds):
var startDate = new Date("Tue Jul 17 2012 00:00:00 GMT+0530");
var startTime = "11:30 AM";
return new Date(+startDate + +new Date("1 1 1970 "+startTime))