dealing with dates on d3.js axis
You're trying to use d3.scale.linear() for dates, and that won't work. You need to use d3.time.scale() instead (docs):
// helper functionfunction getDate(d) { return new Date(d.jsonDate);}// get max and min dates - this assumes data is sortedvar minDate = getDate(data[0]), maxDate = getDate(data[data.length-1]);var x = d3.time.scale().domain([minDate, maxDate]).range([0, w]);Then you don't need to deal with the time interval functions, you can just pass x a date:
.attr("d", d3.svg.line() .x(function(d) { return x(getDate(d)) }) .y(function(d) { return y(d.jsonHitCount) }));Working fiddle here: http://jsfiddle.net/nrabinowitz/JTrnC/