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

Starting Mongo 4.0, this can be achieved with the $toDate aggregation operator:

// { "ts": 1400512120100 }
db.collection.aggregate({ $project: { date: { $toDate: "$ts" } } })
// { "date": ISODate("2014-05-19T15:08:40.100Z") }