Which SchemaType in Mongoose is Best for Timestamp?

I'm using Mongoose, MongoDB, and Node.

I would like to define a schema where one of its fields is a date\timestamp.

I would like to use this field in order to return all of the records that have been updated in the last 5 minutes.

Due to the fact that in Mongoose I can't use the Timestamp() method I understand that my only option is to use the following Javascript method: 

time : { type: Number, default: (new Date()).getTime() }

It's probably not the most efficient way for querying a humongous DB. I would really appreciate it if someone could share a more efficient way of implementing this.

Is there any way to implement this with Mongoose and be able to use a MongoDB timestamp?

Mongoose supports a Date type (which is basically a timestamp):

time : { type : Date, default: Date.now }

With the above field definition, any time you save a document with an unset time field, Mongoose will fill in this field with the current time.

Source: http://mongoosejs.com/docs/guide.html

I would like to use this field in order to return all the records that have been updated in the last 5 minutes.

This means you need to update the date to "now" every time you save the object. Maybe you'll find this useful: Moongoose create-modified plugin