Dates given by new Date and new Date from string differ [duplicate]

When I try to initialize a new Date object, being it 1:18AM at my current location, I get
Thu Apr 13 2023 01:18:16 GMT+0100 (GMT+01:00)

I am working with times in ISO Formats, when I create a new Date object and I pass an ISO String to it, such as
2023-04-12T23:18:15.519Z
I get
Thu Apr 13 2023 00:18:15 GMT+0100 (GMT+01:00)

How can this be? I am implemeting a countdown timer in a React project and this is driving me nuts.

I get the same result upon using Luxon. Any ideas?