Enforcement Rules of the Labor Standards Act Article 11

The basic wage mentioned in Article 21 of the Act refers to remuneration received by a worker for regular working hours, excluding overtime pay and additional payments for overtime work on rest days, holidays and public holidays.
中文原文 勞動基準法施行細則第11條
本法第二十一條所稱基本工資,指勞工在正常工作時間內所得之報酬。
不包括延長工作時間之工資與休息日、休假日及例假工作加給之工資。

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