For a project I'm doing I'm outputting an array of data using `ng-repeat` from AngularJS and am trying to group the output by Month. There's no need to orderBy, since the data I get is already sorted, I just need to group it by Month.

The data I get from the API looks similar like this:

```
{"userinfo": [{
    "date": "1305838800000",
    "name": "john",
    "lastname": "dough",
    "city": "",
    "province": "noord-holland",
    "device": "macbook",
    "phone": "iphone",
    "provider": "t-mobile"
}, {
    "date": "1305838800000",
    "name": "john",
    "lastname": "",
    "city": "amsterdam",
    "province": "noord-holland",
    "device": "macbook",
    "phone": "iphone",
    "provider": "vodafone"
},{
    "date": "1305838800000",
    "name": "john",
    "lastname": "",
    "city": "amsterdam",
    "province": "noord-holland",
    "device": "macbook",
    "phone": "iphone",
    "provider": "t-mobile"
}, {
    "date": "1305838800000",
    "name": "john",
    "lastname": "",
    "city": "amsterdam",
    "province": "noord-holland",
    "device": "macbook",
    "phone": "iphone",
    "provider": "vodafone"
}]}

```

In here the field `field` would be the epoch date of the date I want to group by.

Any help on this grouping matter would be appreciated.