var redefine = require('../internals/redefine'); var DatePrototype = Date.prototype; var INVALID_DATE = 'Invalid Date'; var TO_STRING = 'toString'; var nativeDateToString = DatePrototype[TO_STRING]; var getTime = DatePrototype.getTime; // `Date.prototype.toString` method // https://tc39.github.io/ecma262/#sec-date.prototype.tostring if (new Date(NaN) + '' != INVALID_DATE) { redefine(DatePrototype, TO_STRING, function toString() { var value = getTime.call(this); // eslint-disable-next-line no-self-compare return value === value ? nativeDateToString.call(this) : INVALID_DATE; }); }