I have a json document that looks like this:

```
{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "time": 1438342780,
        "title": "Iran's foreign minister calls for world's nuclear weapons states to disarm",
        "author": "Julian Borger",
        "web_id": "world/2015/jul/31/iran-nuclear-weapons-states-disarm-israel"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          -77.26526,
          38.90122
        ]
      }
    },
    {
      "type": "Feature",
      "properties": {
        "time": 1438300867,
        "title": "Big bangs over the white cliffs of Dover as unique 1915 artillery gun is fired again",
        "author": "Maev Kennedy",
        "web_id": "world/2015/jul/31/big-bangs-over-white-cliffs-dover-unique-1915-artillery-gun-fired-again"
      },
      "geometry": {
        "type": "Point",
        "coordinates": [
          1.3,
          51.13333
        ]
      }
    }
  ]
}

```

I would like to fetch the 'feature' array inside json and return the number of features for a given day. For example, for the data above I would expect something like:

```
{
  "date": 7/31/2015,
  "number": 2
}

```

Currently I have something that looks like this:

```
d3.json('path/to/json', function(json) {
    data = json;
});

```

Fairly new to js and d3 so a bit stumped. Let me know if you need any more details. Thanks in advance!