good day

英 [ˌɡʊd ˈdeɪ]

美 [ˌɡʊd ˈdeɪ]

int. (白天见面或分手时用语)白天好，你(们)好，再见

牛津词典

exclamation

（白天见面或分手时用语）白天好，你（们）好，再见
used to say hello or goodbye politely when people first see each other or leave each other during the day
1. Good day to you.
  你好。

CONVENTION （问候用语，代替Hello及Goodbye）你（们）好，再见
People sometimes say 'Good day' instead of 'Hello' or 'Goodbye'.
1. Well, I'd better be off. Good day to you.
  好啦，我得走了，再见。

noun

Good day to you, Bernard! It's a positive delight to see you
你好，伯纳德！见到你真高兴。
Good day! Let me introduce myself and tell you a few things about who I am.
大家好，让我来介绍一下自己，并告诉你们一些关于我的情况。
Saturday looks like a good day for a personal record.
周六看来是个创个人纪录的好日子。
Well, I'd better be off. Good day to you.
好啦，我得走了，再见。
But you said it wasn't a good day.
但你说今天不是个好日子。
The three friends have a good day.
这三个朋友度过了愉快的一天。
It is a good day to catch up on back reading and other assignments.
周日用来补上拖欠的阅读任务和其他作业的好时机。
Have a good day.
有一个早晨好。
Good morning! Today will be a good day.
早上好！今天会是个好日子。
Say I love you and Have a good day every morning.
每天早晨说我爱你和希望你今天过得开心。