“It be some time+ since短语或从句” 这里面的be用哪种形式呢?is,was还是has been呢

It is 和it has been 都可以
举个例子：
It is two years since I met her last time 自从我和她上次见面,到现在已有两年了
It has been two years since I met her last time 自从我和她山次见面,已经过了两年了
两个句子意思是一样的