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

Tell me about a good day.
和我说说那些美好的日子。
Today is a good day, the rain stopped;
今天是个好日子，大雨停了；
Own good day should end immediately.
自己的好日子马上该结束了。
But you said it wasn't a good day.
但你说今天不是个好日子。
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。
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！
Today is a good day for our barbecue.
今天对我们的烧烤是个好日子。
I'm sorry to complain so much. It's just not a good day.
我很抱歉发了这么多牢骚。今天可不是个好日子。
You could say it was a doggone good day for this golden retriever in Washington State.
你可能会说，对这只华盛顿的金毛猎犬真是糟糕的一天，昨天晚上它坐的汽车翻到了沼泽地上。
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。