Thank you for your response. What I asked you was about, to apply summertime to the work which chose timezone in the existing operation, do I have to change the timezone in that operation to the one which summertime is applied?

문장이 조금 길어서 가독성 있도록 번역했습니다. 원문의 의미는 훼손하지 않았습니다:) 

Thanks for responding. I want to ask that I should change from this operation’s timezone to the timezone applied summertime for applying for summertime on the selected timezone operation from the ordinary operation.