No tax shall be imposed under this section on any excess contribution or excess aggregate contribution, as the case may be, to the extent such contribution (together with any income allocable thereto through the end of the plan year for which the contribution was made) is distributed (or, if forfeitable, is forfeited) before the close of the first 21/2 months (6 months in the case of an excess contribution or excess aggregate contribution to an eligible automatic contribution arrangement (as defined in section
414
(w)(3))) of the following plan year.