new Date() in aggregate $project

Question

For one of my collections, which must remain unix timestamp instead of isodate, I usually convert the timestamp with new Date(unix_timestamp).

Now I need the ne

Answer 1

to be able to add a timestamp field from the document, you can do this, given:

{"ts": 1400512120100}

to aggregate as a date:

db.foo.aggregate({
   $project: {
       date: { $add: [new Date(0), "$ts"] }
   }
})