Migrating momentjs to date-fns

moment-to-datefns.js

/**
The idea here is to replace momentjs with date-fns by using the right api to get the same result
you can test it out in https://repl.it/@waptik/WryElasticNlp
**/

var moment = require("moment")
var {formatRelative, subMonths, sub, isBefore} = require("date-fns");

let newD;
const Subs = sub(1610208638 * 1000, { months: 1}) // using this seems to give me the correct answer
newD = formatRelative(new Date(), 1610208638 * 1000)
newD =subMonths(new Date(newD), 1)
newD = isBefore(newD, new Date())

const newIsBefore = isBefore(Subs, new Date())
console.log("Subs ==>", Subs)

console.log("newIsBefore ==>", newIsBefore) // returns `false` which is correct
console.log("DateFns ==>", newD)// returns `true` which is wrong
console.log("Moment ==>", moment(1610208638 * 1000).subtract(1, 'month').isBefore(new Date()))// returns `false` which is correct