by this time是將來完成時態的標誌詞。

將來完成時指的是到將來某個時間動作已經結束，其結構為will have done ，中文意思是“到將來這個時間”

例如，到明年這個時間，我們將高中畢業了。在最後這段時間各位同學要努力學習爭取考上理想大學。

For example, by this time next year, we will have graduated from high school. In the last period of time, all students should study hard and try to get into the ideal university.

用與現在時間相關的事態。中文意思是在這段時間裡

In this period of time I have been so busy looking after my children that it has been impossible for me to feel unemployed.

現階段，我忙於照顧我的孩子，因此我並沒有失業的感覺。

Even in this period of time after a long time for the past for a long time, I also want to tell you, you for me is priceless.

即使在這段歲月過去以後好久好久之後，我也想告訴你們，你們對我來說是無價之寶。

While in this period of time, many results about Fu study are achieved that provide us with great help for compiling and revising the book.

但是這期間辭：研究卻有很多成果出版，給這部大書的編寫和修改提供了很大的幫助。