wcf-date Converts between WCF date and JavaScript Date object. Install npm install wcf-date Use Module Node.js let wcfDate = require("wcf-date"); Browser <script src="node_modules/wcf-date/lib/wcf-date.js" /> Demo let wcfDate = require("wcf-date");let s = "/Date(1408431600000-0700)/";let d = wcfDate.parseWcfDate(s);// 2014-08-19T06:59:59.300Zlet s2 = wcfDate.toWcfDateString(d);// "/Date(1408431599300)/"