Custom JS to extract age in Adobe Launch and Google Tag Manager From A Timestamp

Adobe Launch - Custom JavaScript - Get age of user from dataLayer variable.js

//Custom JS to get age of user in Adobe Launch
var x=_satellite.getVar('dataLayer var: DOB');
var dobYear = x.getFullYear();
var curYear = new Date().getFullYear();
var age = curYear - dobYear;

return age;

Google Tag Manager - Custom JavaScript - Get age of user from dataLayer variable.js

//Custom JS to get age of user in Google Tag Manager.
var x={{dataLayer var: DOB}};
var dobYear = x.getFullYear();
var curYear = new Date().getFullYear();
var age = curYear - dobYear;

return age;