Standard for Popularized Delivery Services Article 7

Except for national holidays or unless otherwise provided by other laws and regulations, the collection and delivery of the popularized delivery services shall be done at least five days per week. However, this restriction shall not apply to those with the consent of the competent authority.Chunghwa Post shall mark the number and time of opening and taking out on the dedicated equipment for collecting documents or articles, and open it and take them out on schedule.
中文原文 遞送普及服務標準第7條
遞送普及服務之收攬及投遞班次,除國定假日或其他法令另有規定外,每週收投日數至少為五日。
但經主管機關同意者,不在此限。
中華郵政公司應於收受文件或物品專用器具上標示開取之次數和時間,並按時開取。

English translation for reference only; the Chinese text prevails. Not legal advice.