Public officials Election And Recall Act Article 15

A person who has the right of suffrage and who has been living in an electoral district for not less than four consecutive months is a voter for elections for public office in that electoral district.The length of residence specified in the preceding paragraph shall be calculated with respect to the entire administrative area even if the said area is divided into several electoral districts. However, persons who move into an electoral district after public notice for election has already been issued have no right of suffrage.
中文原文 公職人員選舉罷免法第15條
有選舉權人在各該選舉區繼續居住四個月以上者,為公職人員選舉各該選舉區之選舉人。
前項之居住期間,在其行政區域劃分選舉區者,仍以行政區域為範圍計算之。
但於選舉公告發布後,遷入各該選舉區者,無選舉投票權。

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