rea.xmin);
		// go to the first Saturday
		d.setDate(d.getDate() - ((d.getDay() + 1) % 7))
		d.setSeconds(0);
		d.setMinutes(0);
		d.setHours(0);
		var i = d.getTime();
		do {
			areas.push({ x1: i, x2: i + 2 * 24 * 60 * 60 * 1000 });
			i += 7 * 24 * 60 * 60 * 1000;
		} while (i < plotarea.xmax);

		return areas;
	}
	function showTooltip(x, y, contents) {
		$('<div id="hovertip">' + contents + '</div>').css( {
			position: 'absolute',
			display: 'none',
			top: y + 5,
			left: x + 15,
