How to convert NumberLong to Date in MongoDB's shell?

Question

I am storing unix timestamp as MongoDB's NumberLong type (millisecond) , how to convert to human readable date string in the Mongo shell?

Solution 1

NumberLong(123123123123131).toNumber().toString()

Solution 2

For my own future reference (and incorporating the other answers):

db.mycollection.aggregate([
  {$match:{"userId":"d1792d83-d854-44d5-9jc5-e3e20435958b"}},
  {$project:{newDate:Date("$numberLongDate")}}
])

Solution 3

I'm using expressions like that:

>Date(NumberLong("1397051113715")); 

it will be work too.

Comments

[JohnnyHK]

1413382500151 is just a Number type, not a NumberLong.

[fred271828]

On second view, this doesn't seem to work. It's returning the same Date for every $numberLongDate.

[fred271828]

Here's the fix: newDate:{$add: [new Date("1970-01-01"), "$numberLongDate"]}.

[davo777]

Hi fwc, I've been trying to emulate your code above and when I run it it returns Nulls in all the new date columns. Can you see what I'm doing wrong? db.mycoll.aggregate([ {$project:{newDate: {$add: [new Date("1970-01-01"), "$numberLongDate"]}}}])

[fred271828]

Tough to tell, $numberLongDate needs to be the name of your date field maybe?