大后天是星期几用英文怎么说

"大后天"的英文表达是 "the day after tomorrow"。这个短语来源于英语中对时间的描述方式，"tomorrow" 意为 "明天"，"the day after tomorrow" 就是 "后天"。

例句1:

Engpsh: I will meet you the day after tomorrow.
中文: 我大后天和你见面。

例句2:

Engpsh: The day after tomorrow is Friday.
中文: 大后天是星期五。