How to add +9 hours on my jQuery script? - php

Question

How can I add +9 hours on my script below ? I don't prefer to just add 9 hours to the correct time, for example if I want it 13:22:54 to make it 22:22:54 for this to work but on the script.
I create the unix timestamp in a php file doing
$end = mktime(16, 54, 0, 8, 18, 2011);
and the copy it below
Countdown Script
<script type="text/javascript">
var end_date = new Date(<?php echo $end; ?>*1000);
$(document).ready(function() {
$("#time").countdown({
date: end_date,
onComplete: function( event ){
$(this).html("completed");
},
leadingZero: true
});
});
</script>
<p id="time" class="time"></p>

Answer 1

Instead of playing the heroes by trying to do time Math (and even failing badly), you should rely on native methods, available to both PHP and JS:
// gets the time 9 hours from now
// you can give a 2nd parameter to specify when is "now"
$date = strtotime('+9 hours');
and:
// get the time right now
var date = new Date()
// add 9 hours, don't worry about jumping the 24hr boundary, JS resolves correctly.
date.setHours(date.getHours()+9)
Edit:
Since the OP said he wanted to use a TS from DB, here's the relevant code:
$date = strtotime('+9 hours', (int)$db_time);
Note: If $db_time is a formatted string, like "24 April 2011, 4:56 pm", you need to put the following code before the one above:
$db_time = strtotime($db_time);
However, I urge you to check for alternative ways to parse the time.

Answer 2

I'm going to read between the lines here a bit. I assume based on this and previous questions that you want a countdown for some event in the future and you're pulling a timestamp from a database and adding 9 hours to it to get the time of that future event.
Assuming this, you can't use most (any?) of the previous answers because of time zones and the fact that the user's clock might be more or less off. So if you calculate on the server that the event should fire at 5 o'clock and send that info to the user who's 3 time zones away from the server, the countdown will also be 3 hours off (because when it's 5 o'clock where the user is it's either 2 or 8 o'clock where the server is.)
The solution is to calculate the time left until the event and send that information to the browser. This way the countdown will be independent of the user's timezone or their computer's clock. For example if the event is at 5 o'clock and it's now 4 o'clock tell the browser to put 60*60*1=3600 seconds on the timer.
Using part of Christian's answer, do something like this on the server (assuming $db_time contains a Unix timestamp retrieved from the database):
$date = strtotime('+9 hours', (int)$db_time);
$timeUntilEvent = $date - time();
Now $timeUntilEvent contains the amount of seconds until the event. In JavaScript add that number to the timer:
var end_date = new Date();
end_date.setTime( end_date.getTime() + <?php echo $timeUntilEvent; ?> * 1000 );
Now the timer will fire at the correct time regardless of what time the user's clock is set to.

Answer 3

var end_date = new Date((<?php echo $end; ?>+32400)*1000);

Answer 4

end_date = end_date + ((3600*1000)*9);

Answer 5

mktime returns seconds, so you simply add the desired amount of seconds
using the end_date created with php, add this line:
end_date+=9*60*60

Answer 6

Call this before your countdown:
end_date = end_date.setTime((end_date + (9 * 3600)) * 1000).toGMTString();
EDIT: I removed the get_time() and the "* 1000" as end_date is already a UNIX timestamp.
EDIT2: Apparently, timestamps in js are in milliseconds so we also have to multiply the PHP timestamp (which is in seconds).