时间表达式可能令人困惑。THE用于某些时间表达式，例如：在早晨、下午、晚上、在晚上、白天、前天、后天、秋天、夏天
例如1：
We'll meet in the afternoon.
我们下午见面。
Jake loves to go camping in the fall.
杰克喜欢在秋天去露营。
There was a small earthquake during the night.
夜间发生了小地震。
HOWEVER: In other time expressions, no article is used:
但是：在其他时间表达中，不使用冠词：在晚上、中午、在午夜、一整天、通宵、整个月、每个月、每年、昨晚、上周五、昨天、明天
例如2：
Did you sleep well last night?
你昨晚睡得好吗？
I'll see you tomorrow.
明天见。
We are meeting for lunch at noon.
我们中午见面吃午饭。
MOREOVER: There are some expressions which can take both A(AN) and THE such as:
此外：有些表达式可以同时采用A(AN)和THE，例如：
一/一整天
a/整个月
一个/全年
一个/整个十年
例如3：
He spent a whole month in Hawaii. I wish I could do that.
他在夏威夷待了整整一个月。我希望我能做到。
I took last Friday off to go to the doctor. I spent the whole day sitting in his office.
我上周五请假去看医生。我整天坐在他的办公室里。
When she first moved to Germany, it took an entire year for her to learn enough German to go shopping.
当她次搬到德国时，她花了整整一年的时间才学会了足够的德语去购物。
Phil hated the '90s. He spent the whole decade in a dead-end job struggling to pay his rent.
菲尔讨厌 90 年代。他花了整整十年的时间在一个死胡同的工作中挣扎着支付他的房租。