moment().duration().toJSON();

npm install moment

const moment = require('moment'); 
  
// Example 1 
let publishTime = moment(); 
  
let article = { 
    title: "Article One", 
    publishTime: publishTime.toJSON() 
} 
  
console.log( 
    "Article Details:", JSON.stringify(article) 
)

Article Details: {
    "title":"Article One",
    "publishTime":"2022-06-28T18:19:35.621Z"
}

const moment = require('moment'); 
  
let startTime = moment(); 
let endTime = startTime.add(15, 'minutes'); 
  
let timeCalculation = { 
    startTime: startTime.toJSON(), 
    endTime: endTime.toJSON() 
} 
  
console.log( 
    "Duration:", JSON.stringify(timeCalculation) 
)

Duration: {
    "startTime":"2022-06-28T18:34:35.630Z",
    "endTime":"2022-06-28T18:34:35.630Z"
}