javascriptdatemomentjsluxon

How to parse UNIX timestamps with luxon?

I tried to use the luxon library to move away from moment - to translate the 1615065599.426264 timestamp into an ISO date.

According to the Online Epoch Converter this corresponds to

GMT: Saturday, March 6, 2021 9:19:59.426 PM
Your time zone: Saturday, March 6, 2021 10:19:59.426 PM GMT+01:00
Relative: 3 days ago

Removing the decimal part gives the same result.

The code using luxon:

let timestamp = 1615065599.426264
console.log(luxon.DateTime.fromMillis(Math.trunc(timestamp)).toISO())
console.log(luxon.DateTime.fromMillis(timestamp).toISO())
<script src="https://moment.github.io/luxon/global/luxon.min.js"></script>

This result is

1970-01-19T17:37:45.599+01:00
1970-01-19T17:37:45.599+01:00

It is suspiciously close to Unix Epoch (1970-01-01 00:00:00).

Where is my mistake?

Solution

  • Just to give a more complete answer, there are indeed 2 ways of storing timestamps: Seconds and milliseconds precisions.

    JavaScript indeed uses ms precision by default.

    Luxon provides 2 different methods:

    Both will produce the same output when calling date.toISO():

    Depending on which precision you use, you need to use one or the other.

    I wrote this answer because the other answer didn't make that crystal clear, and I found myself using toSeconds when what I really wanted was toMillis.