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

Too good today, that is a good day yesterday!
过好了今天，也就是明天有了好的昨天！
It was a good day for outdoor activities, as I had stayed at home for a period.
我在家里呆了有一段时间了，是出门活动的好机会。
Tell me about a good day.
和我说说那些美好的日子。
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。
Today was a good day and a bad day.
今天是一个好日子，也是一个坏日子。
I hope that all of you have a good day.
我希望你们都有美好的一天。
Good day to you, Bernard! It's a positive delight to see you
你好，伯纳德！见到你真高兴。
We did a good day's work yesterday.
昨天我们整整工作了一天。
It's a good day for playing practical jokes on your friends.
这是一个对你的朋友们开实际玩笑的好日子。
It's a good day for an important meeting because things are sure to go your way.
这也是个举行重要会议的好日子，因为事情开始顺应你的期待而动了。