time表示次数作为先行词时的定语从句,为什么此时that是关系代词?that应该是不作为成分的啊

先行词是名词,that做引导词时,可能是同位语从句,也可能是定语从句.
同位语从句：从句中除去that仍是一个完整的句子可判定为同位语从句,同位语从句是用来解释说明前面的先行词,that不指代主句任何名词,也不担当从句中任何成分,从句中除去that后剩下的完整句子指代先行词.
定语从句：从句中除去that就不是一个完整的句子可判定为定语从句,定语从句是用来修饰前面先行词,that指代先行词,同时在从句中必须担当一个名词成分,这就注定它是关系代词.
I want to tell you the news (that you won the game),
从句除去that,剩余部分You won the game是一个完整句子,所以这是一个同位语从句, You won the game指代先行词the news,the news=You won the game.,that不担当主句和从句中任何成分,
I want to tell you the news that I just got few minutes ago.
从句除去that就不是一个完整的句子,I just got few minutes ago缺少宾语,所以这是一个定语从句,that在从句中担任宾语,同时指代先行词the news,that=the news,是关系代词..

引导定语从句的是关系词，而它又分为关系副词和关系代词：关系副词(when where why how...)不做主要成分；关系代词(that which but as...)一般可做主、宾、表语
由此可见作为关系代词的that是必须要做成分的，做主宾表，与谁是先行词无关。