var createNonEnumerableProperty = require('../internals/create-non-enumerable-property'); var dateToPrimitive = require('../internals/date-to-primitive'); var wellKnownSymbol = require('../internals/well-known-symbol'); var TO_PRIMITIVE = wellKnownSymbol('toPrimitive'); var DatePrototype = Date.prototype; // `Date.prototype[@@toPrimitive]` method // https://tc39.github.io/ecma262/#sec-date.prototype-@@toprimitive if (!(TO_PRIMITIVE in DatePrototype)) { createNonEnumerableProperty(DatePrototype, TO_PRIMITIVE, dateToPrimitive); }