Please refer to Civil Code of the Philippines (Obligations and Contracts) to answer the following. Kindly include specific article number where you based your answer.

X sold Y 100 sacks of rice that Y was to pick up from X's rice mill on a particular date. Y did not, however, appear on the agreed date to take delivery of the rice. After one week, X automatically rescinded the sale without notarial notice to Y. Is the rescission valid?