Vue.js How to make a select with timeZones

Question

I want to have a select with Vue.js because I want to be able to select de different timeZones of the world

My first question would be: What is the best library to do this kind of select component showing, for instance, Europe/Warsaw (GMT+1)?

After make a search over internet I've found a library that can be my solution: https://www.npmjs.com/package/@vvo/tzdb but it doesn't offer the info related to Greenwich Mean Time(GMT), instead I can have it like this: Europe/Warsaw (CET)

What can be recommended in this case?

PS: this is an example of all the data can be obtained in a single timeZone:

{ "name": "Pacific/Niue", "alternativeName": "Niue Time", "group": [ "Pacific/Niue" ], "continentCode": "OC", "continentName": "Oceania", "countryName": "Niue", "countryCode": "NU", "mainCities": [ "Alofi" ], "rawOffsetInMinutes": -660, "abbreviation": "NUT", "rawFormat": "-11:00 Niue Time - Alofi", "currentTimeOffsetInMinutes": -660, "currentTimeFormat": "-11:00 Niue Time - Alofi" }

EDIT For more explicit detail, I am looking for a way of obtaining GMT from the other time zones abbreviature...and I use an example: from here Europe/Warsaw (CET) to here Europe/Warsaw (GMT+1)