Edit in JSFiddle

var data = [{"end_time":"2013-01-01","value":25.00},{"end_time":"2013-01-02","value":0.00},{"end_time":"2013-01-03","value":25.00},{"end_time":"2013-01-04","value":159.00},{"end_time":"2013-01-05","value":84.00},{"end_time":"2013-01-06","value":0.00},{"end_time":"2013-01-07","value":64.00},{"end_time":"2013-01-08","value":84.00},{"end_time":"2013-01-09","value":84.00},{"end_time":"2013-01-10","value":0.00},{"end_time":"2013-01-11","value":89.00},{"end_time":"2013-01-12","value":75.00},{"end_time":"2013-01-13","value":0.00},{"end_time":"2013-01-14","value":50.00},{"end_time":"2013-01-15","value":50.00},{"end_time":"2013-01-16","value":174.00},{"end_time":"2013-01-17","value":84.00},{"end_time":"2013-01-18","value":0.00},{"end_time":"2013-01-19","value":393.00},{"end_time":"2013-01-20","value":134.00},{"end_time":"2013-01-21","value":282.00},{"end_time":"2013-01-22","value":25.00},{"end_time":"2013-01-23","value":149.00},{"end_time":"2013-01-24","value":0.00},{"end_time":"2013-01-25","value":124.00},{"end_time":"2013-01-26","value":100.00},{"end_time":"2013-01-27","value":134.00},{"end_time":"2013-01-28","value":168.00},{"end_time":"2013-01-29","value":379.00},{"end_time":"2013-01-30","value":193.00},{"end_time":"2013-01-31","value":0.00}]

var m = [80, 80, 80, 80],
    w = 700 - m[1] - m[3],
    h = 250 - m[0] - m[2],
    parse = d3.time.format("%Y-%m-%d").parse;

var x = d3.time.scale().range([0, w]),
    y = d3.scale.linear().range([h, 0]),
    xAxis = d3.svg.axis().scale(x).tickSize(-h).tickFormat(d3.time.format("%-m/%d")),
    yAxis = d3.svg.axis().scale(y).ticks(2).orient("right");

var area = d3.svg.area()
    .interpolate("linear")
    .x(function (d) {
    return x(d.end_time);
})
    .y0(h)
    .y1(function (d) {
    return y(d.value);
});

var line = d3.svg.line()
    .interpolate("linear")
    .x(function (d) {
    return x(d.end_time);
})
    .y(function (d) {
    return y(d.value);
});

data.forEach(function (d) {
    d.end_time = parse(d.end_time);
    d.value = +d.value;
});

var total = 0
for (var i = 0, len = data.length; i < len; i++) {
    total += data[i].value;
}

x.domain([data[0].end_time, data[data.length - 1].end_time]);
y.domain([0, d3.max(data, function (d) {
    return d.value;
})]).nice();

var svg = d3.select("body").append("svg:svg")
    .attr("width", w + m[1] + m[3])
    .attr("height", h + m[0] + m[2])
    .append("svg:g")
    .attr("transform", "translate(" + m[3] + "," + m[0] + ")");

svg.append("svg:path")
    .attr("class", "area")
    .attr("d", area(data));

svg.append("svg:g")
    .attr("class", "x axis")
    .attr("transform", "translate(1," + h + ")")
    .call(xAxis);

svg.append("svg:g")
    .attr("class", "y axis")
    .attr("transform", "translate(" + w + ",0)")
    .call(yAxis);

svg.selectAll("line.y")
    .data(y.ticks(5))
    .enter().append("line")
    .attr("x1", 0)
    .attr("x2", w)
    .attr("y1", y)
    .attr("y2", y)
    .style("stroke", "#000000")
    .style("stroke-opacity", 0.06);

svg.append("svg:path")
    .attr("class", "line")
    .attr("d", line(data));

svg.append("svg:text")
    .attr("x", 80)
    .attr("y", -10)
    .attr("text-anchor", "end")
    .text('Gross Volume')
    .style("stroke", "#444")
    .style("fill", "#000")
    .style("stroke-width", .2)
    .style("font-size", "12px")
    .style("font-weight", "bold");

svg.append("svg:text")
    .attr("x", w)
    .attr("y", -10)
    .attr("text-anchor", "end")
    .text('$' + total.toFixed(2) + " total")
    .style("stroke", "#008cdd")
    .style("fill", "#008cdd")
    .style("stroke-width", .2)
    .style("font-size", "12px")
    .style("font-weight", "bold");

svg.selectAll("circle")
    .data(data)
    .enter().append("circle")
    .attr("fill", "#008cdd")
    .attr("r", 4)
    .attr('cx', function (d) {
    return x(d.end_time);
})
    .attr('cy', function (d) {
    return y(d.value);
});