Sand and Gravel Excavation Act Article 16

When a sand and gravel excavator applies for an extension pursuant to Article 6, the application shall be filed no later than six months before the expiration date. However, if the validity period of the permit is one year or less, the application shall be filed no later than two months before the expiration date.
中文原文 土石採取法第16條
土石採取人依第六條規定為展限之申請時,應於期滿六個月前為之。
但土石採取許可期限在一年以內者,應於期滿二個月前為之。

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