Aggregation Framework - Converting Unix Timestamp to ISODate

Question

Say I have a collection with objects like this, where the ts property contains an Unix Timestamp.

{ 
  "_id" : ObjectId("50ef1e0f1e816a74ad835a5a"), 
  "ts" : 1357851660 
}

Is there a way to convert the ts field to an ISODate using the Aggregation Framework, so I can use the date operators ($dayOfYear, $dayOfMonth, ...)?

Good question. I can only think of doing this with MapReduce, but that feels like using a shotgun for a flea. — mjhm, Jan 11 '13 at 01:45
I've answered this in the linked StackOverflow question: http://stackoverflow.com/a/27828951/572077 — Astral, Jan 07 '15 at 21:29

score 5 · Accepted Answer · answered Jan 18 '13 at 13:14

5

All information and testing I could find out indicates this is not possible as of MongoDB 2.2.2. It's fairly easy to implement using Map/Reduce though.

Marking this as answered as this seems to be the best answer available right now, but I'm willing to review this in the future if new functionality is added to MongoDB to support this, or if someone comes up with a good workaround.

answered Jan 18 '13 at 13:14

Badaro

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whats your map reduce algo, if you dont mind – Gabe Rainbow Feb 07 '14 at 02:29

Aggregation Framework - Converting Unix Timestamp to ISODate

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