MongoDB Tips - Using _id to determine when the object was inserted
MongoDB objectid conversion to timestamp Basically we can generate timestamp when this document is inserted by converting the objectid to timestamp: Please look at the following for javascript by Steve Ridout on his blog https://steveridout.github.io/mongo-object-time/ Why generate an ObjectId from a timestamp? To query documents by creation date. e.g. to find all comments created after 2013-11-01: db.comments.find({_id: {$gt: ObjectId("5272e0f00000000000000000")}}) Javascript functions var objectIdFromDate = function (date) { return Math.floor(date.getTime() / 1000).toString(16) + "0000000000000000"; }; var dateFromObjectId = function (objectId) { return new Date(parseInt(objectId.substring(0, 8), 16) * 1000); };