Core Legal Answer & Context: When a transfer is made for the benefit of an unborn person, the timing of the acquisition of a vested interest is crucial. According to Section 20 of the Transfer of Property Act, 1882, an unborn person acquires a vested interest in the property upon his birth, unless a contrary intention is expressed in the terms of the transfer. This means that the interest becomes fixed and indefeasible as soon as the person comes into existence, irrespective of whether they have attained majority or any other specified age.

Relevant Statutes and Sections: Transfer of Property Act, 1882, Section 20 (When unborn person acquires vested interest).

Important Landmark Cases: Not applicable for a direct statutory provision.

Clear Conclusion: An unborn person acquires vested interest as soon as he is born.