Is it possible to use Date rather than version number?

[sholtomaud]

Let's say you are interested to know the dates that different fields were updated in a document.

Am I able to use a Date field rather than "version"? Or does this feature already exist and I'm showing my nativity?

Currently data would look like this (I assume):

{
  _id: "4c6b9456f61f000000007ba6"
  latitude: [
    { version: 1, value: 141.1100011 },
    { version: 6, value: 141.1252105 }
  ]
}

Proposed Option would be stored like this

{
  _id: "4c6b9456f61f000000007ba6"
   latitude: [
    { date: 20150101, value: 141.1100011 },
    { date: 20150201, value: 141.1252105 }
  ]
}

[Ghalleb]

I had the same concern and ending up using
mongoose timestamps option property in my shema:
http://mongoosejs.com/docs/guide.html#timestamps
That did the trick