RunKit + npm: d3-time-format

var d3 = require("d3-time-format"); var parseMilliseconds = d3.utcParse("%Y-%m-%dT%H:%M:%S.%LZ"), stripNanoseconds = function(s) { return s.slice(0, -4) + "Z"; }, parseTime = function(s) { return parseMilliseconds(stripNanoseconds(s)); }; parseTime("2016-10-06T20:32:56.523411Z").toUTCString();