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I cant seem to work out why the time on the x axis is always an hour behind.
I know its got something to do with this line but I cant work out what to change it to.
date = Date.parse(line[0] + ' UTC');
My current timezone is London.
I've got this file: index.php
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>Using Highcharts with PHP and MySQL</title>
<script type="text/javascript" src="js/jquery-1.7.1.min.js" ></script>
<script type="text/javascript" src="js/highcharts.js" ></script>
<script type="text/javascript" src="js/themes/gray.js"></script>
<script type="text/javascript">
var chart;
$(document).ready(function() {
var options = {
chart: {
renderTo: 'container',
defaultSeriesType: 'line',
marginRight: 130,
marginBottom: 25
},
title: {
text: 'Temperature for the last hour',
x: -20 //center
},
subtitle: {
text: '',
x: -20
},
xAxis: {
type: 'datetime',
tickInterval: 3600 * 1000, // one hour
tickWidth: 0,
gridLineWidth: 1,
labels: {
align: 'center',
x: -3,
y: 20,
formatter: function() {
return Highcharts.dateFormat('%H:%M', this.value);
}
}
},
yAxis: {
title: {
text: 'Temperature'
},
plotLines: [{
value: 0,
width: 1,
color: '#808080'
}]
},
tooltip: {
formatter: function() {
return Highcharts.dateFormat('%H:%M', this.x-(1000*3600)) +': <b>'+ this.y + '</b>';
}
},
legend: {
layout: 'vertical',
align: 'right',
verticalAlign: 'top',
x: -10,
y: 100,
borderWidth: 0
},
series: [{
name: 'Temperature'
}]
}
// Load data asynchronously using jQuery. On success, add the data
// to the options and initiate the chart.
// This data is obtained by exporting a GA custom report to TSV.
// http://api.jquery.com/jQuery.get/
jQuery.get('data.php', null, function(tsv) {
var lines = [];
traffic = [];
try {
// split the data return into lines and parse them
tsv = tsv.split(/\n/g);
jQuery.each(tsv, function(i, line) {
line = line.split(/\t/);
date = Date.parse(line[0]);
traffic.push([
date,
parseFloat(line[1].replace(',', ''), 10)
]);
});
} catch (e) { }
options.series[0].data = traffic;
chart = new Highcharts.Chart(options);
});
});
</script>
</head>
<body>
<div id="container" style="width: 100%; height: 400px; margin: 0 auto"></div>
</body>
</html>
I've tried fiddling around with settings like
date = Date.parse(line[0] + ' Europe/London');
date = Date.parse(line[0] + ' London');
I have also tried putting this at the top of the php file:
<?php date_default_timezone_set('Europe/London'); ?>
data.php spits out:
2013-09-15 11:49:42 18.3 2013-09-15 11:52:42 18.4 2013-09-15 11:55:42 18.4 2013-09-15 11:58:42 18.4 2013-09-15 12:01:42 18.3 2013-09-15 12:04:42 18.5 2013-09-15 12:07:42 18.6 2013-09-15 12:10:43 18.6 2013-09-15 12:13:43 18.8 2013-09-15 12:16:43 19 2013-09-15 12:19:43 19.3 2013-09-15 12:22:43 19.4 2013-09-15 12:25:43 19.5 2013-09-15 12:28:43 19.6 2013-09-15 12:31:43 19.8 2013-09-15 12:34:45 20.1 2013-09-15 12:37:43 20.1 2013-09-15 12:40:43 20.2 2013-09-15 12:43:43 20.3 2013-09-15 12:46:43 20.3
where the times are correct.
I've now added in:
Highcharts.setOptions({
global: { useUTC: false }
});
The tickmarks are correct but the times displayed on the tooltip are still an hour behind.
Update: Found the problem - I need to add the useUTC: false option as suggested, and then change the following line as well:
return Highcharts.dateFormat('%H:%M', this.x-(1000*3600)) +': <b>'+ this.y + '</b>';
to
return Highcharts.dateFormat('%H:%M', this) +': <b>'+ this.y + '</b>';
859
London uses BST during the summer and GMT during the winter. See: here
BST is the equivalent to UTC +1. That's important information to know for this reason: the result you are getting back is UTC, not BST. If you wish to retrieve the local time, then it is necessary to set the global option for useUTC: false. See: here.
This page gives an example of how to properly set your global options: link
Essentially, what you need to add is the following:
global: {
useUTC: false
}
For me the useUTC: false was enough. Maybe you can try also timezoneOffset. But for me it works with useUTC.
My full code looks like this:
Highcharts.setOptions({
global: {
// timezoneOffset: +1,
useUTC: false
}
});
More info will be in documentation - http://api.highcharts.com/highcharts#global
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