Experimente o tempo em JavaScript

const unixTimeZero = Date.parse('01 Jan 1970 00:00:00 GMT');
const javaScriptRelease = Date.parse('04 Dec 1995 00:12:00 GMT');

console.log(unixTimeZero);
// expected output: 0

console.log(javaScriptRelease);
// expected output: 818035920000
Undefined