消滅時效 期間起算點 請求權可行使時 主觀判斷基準 客觀判斷基準 法律上障礙 時效停止進行制度 法理 誠實信用原則 Extinctive prescription The moment of the prescription that starts The moment of being exercised Subjective judging standard Objective judging standard Legal defect The interruption of the prescription system Legal principle Bona fide Good faith principle