Enforcement Rules of the Customs Act Article 16

The expression "exported at or about the same time"referred to in Article 31, Paragraph 1, and Article 32, Paragraph 1, of the Act shall mean within 30 days before or after the date of exportation.The expression "at or about the time of the importation" pursuant to Article 33, Paragraph 3 and Paragraph 4, of the Act shall mean within 30 days before or after the date of importation.
中文原文 關稅法施行細則第16條
本法第三十一條第一項及第三十二條第一項所稱出口前、後,指出口日前後三十日內。
本法第三十三條第三項及第四項所稱進口前、後,指進口日前後三十日內。

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