let unixTime = 1661354615;//it is time from 1970 in seconds
let date = new Date(unixTime*1000);//convert to milliseconds as javascript store number in milliseconds
console.log(date) //Wed Aug 24 2022 21:08:35 GMT+0545 (Nepal Time)
//it will display your localtime with GMT +545 which means 5 hours 45 minutes forward from london.
console.log(date.toUTCString()) //'Wed, 24 Aug 2022 15:23:35 GMT'