I took an example from google and fill an array of data with other data and found that the behavior is identical.
<html>
<head>
<script type="text/javascript">
google.load("visualization", "1", {packages:["corechart"]});
google.setOnLoadCallback(drawChart);
function drawChart() {
var data = new google.visualization.DataTable();
data.addColumn('date', 'Date');
data.addColumn('number', 'Calorie');
data.addRows( [
[new Date(2012,7,1), 400],
[new Date(2012,7,2), 460],
[new Date(2012,7,3), 770],
[new Date(2012,7,4), 540],
[new Date(2012,7,5), 400],
[new Date(2012,7,6), 460],
[new Date(2012,7,7), 770],
[new Date(2012,7,8), 400],
[new Date(2012,7,9), 460],
[new Date(2012,7,10), 770],
[new Date(2012,7,11), 540],
[new Date(2012,7,12), 400],
[new Date(2012,7,13), 460]
]);
var options = {
title: 'Company Performance',
hAxis: {title: 'Date',
titleTextStyle: {color: 'red'},
minTextSpacing:1,
slantedText:true,
slantedTextAngle:90,
showTextEvery:1,
textStyle:{color: '#333333', fontSize: 9},
format:'dd'
}
};
var chart = new google.visualization.ColumnChart(document.getElementById('chart_div'));
chart.draw(data, options);
}
</script>
</head>
<body>
<div id="chart_div" style="width: 900px; height: 500px;"></div>
</body>
</html>