JS timestamp wrong – timezone setting

When setting a date from a timestamp using JS, I obtain the wrong hour.

var timestamp = 1548374400000 //In milliseconds.
var time_string =  new Date(timestamp).toLocaleString("en-GB",{timezone:"Europe/London"})
console.log(time_string)

Which outputs:

25/01/2019, 01:00:00

However when checking on the following website: https://www.epochconverter.com/timezones?q=1548374400000&tz=Europe%2FLondon

I obtain that this timestamp (1548374400000) corresponds to the date: Friday January 25, 2019 00:00:00 (am) in time zone Europe/London (GMT)

There is a one hour difference between these results that I cannot explain myself.

I have checked on this website to be sure this was an error on my side:

>Solution :

var timestamp = 1548374400000; // In milliseconds.
var time_string = new Date(timestamp).toLocaleString("en-GB", { timeZone: "Europe/London" });
console.log(time_string);

You just used the wrong keyword. Use code above should fix your problem.