JSFiddle - React, Tailwind, and code Playground
JavaScript
var data = '/Date(1508551200000)/';
data = new Date(parseInt(data.replace(/\/Date\((-?\d+)\)\//, '$1'))).toLocaleString('pt-BR', { timeZone: 'America/Sao_Paulo' });
var dt = data.substring(0, 10).split("/");
data = new Date(dt[2], dt[1] - 1, dt[0]);
alert(data);