Is using timestamp to initialize Date affected by timezone?

Question

My local machine timezone is Asia/China , UTC+8.

new Date(1509692400000).toISOString() // output: 2017-11-03T07:00:00.000Z

When I change the timezone environment variable export TZ=Europe/Amsterdam , I got the same ISO string of the date.

new Date(1509692400000).toISOString() // output: 2017-11-03T07:00:00.000Z

Does this mean using a timestamp to initialize Date , not affected by timezone?

So I can use this way to mock the Date when running the unit tests on different remote CI servers with different timezones.

Answer 1

As says documentation , toISOString() method always returns timezone UTC-0. In my opinion, if you want to use date in unit tests, shared in unknown-location servers, then setup Date object as you did and check date using toUTCString() - docs