Fawn unable to save createdAt

[pallabpki]

Hi...I am trying to save data but record saving withoit createdAt, and updatedAt. But when I am saving normally it's saving properly.

{
    timestamps: true
}

Already added in Schema
//Fawn

new Fawn.Task()
   .save('employees', employee)
   .save('employeedetails', employeeDetails)
   .run({ useMongoose: true })
   .then(function (retult) {
      res.send({
         retult
      })
   })