Generate random value in json

{
  "description": "Appname",
  "name": "appname",
  "partnerProfile":  {
    "email": "aa@gmail.com",
    "firstName": "John",
    "lastName": "Jobin",
    "partnerName": "app"
  }
}

I am passing the following body in a json file. How do I generate random value(time stamp) for partnerName for different test run. I am using Newman to run the script

Newman run Automation.json -e Dev.json -r html