MomentJS : Issue subtracting minutes

Question

This is my code that is deployed on Parse.com CloudCode :

var now = new Date()
var then = moment(now).subtract(20, "minutes").toDate()

console.log(now)
console.log(then)

Why does now === then ?

What am I doing wrong ?

Answer 1

One line answer:

moment(Date.now()).subtract(60, 'minutes').format()

Answer 2

I don't know you were wrong, but for me works properly. No issues.

>var now = new Date()
>var then = moment(now).subtract(20, "minutes").toDate()
>console.log(now)
>console.log(then)
VM145:5 Thu Jan 21 2016 17:26:48 GMT+0100 (CET)
VM145:6 Thu Jan 21 2016 17:06:48 GMT+0100 (CET)
undefined
>now === then
false

Answer 3

I had the same issue and had to do something similar to this:

const now = new Date()
const nowCopy = new Date()
const then = moment(nowCopy).subtract(20, "minutes").toDate()

console.log(now)
console.log(then)

I know it's not the most elegant solution but it appears your "now" variable is getting mutated when you run an operation on it to get your "then" variable