1. be up: if the time allowed for something is up , it is finished

例：

"Time's up,'' said the teacher."Stop writing, everyone!''（老师说：“同学们，时间到，大家都停笔。”）

The chairman may be asked to resign before his four-year term is up. （主席在四年任期满前可能就会被要求下课。）

补充：这里的"up"有表示“用尽”的意思。再如以下几个例句中的"up"：

We've used up all our savings. （我们的积蓄都花光了。）

The children had to eat up all their food. （孩子们不得不吃完自己碗里的东西。）

After a month, the wound had almost healed up. （一个月后，伤口差不多都愈合了。）

2. run out: if the time available for doing something, especially something important, runs out , it comes to an end so that there is no more time left

例：

We must act now because time is running out. （时间不多了，我们得马上行动。）

We'd almost finished solving the problem when our time ran out. （在规定时间内，我们差不多把问题解决了。）

The desperate search for survivors continues, but time is running out. （仍在搜寻幸存者，但是时间一分一秒过去，希望越来越渺茫。）

补充：''time is running out''的反义词组“有得是时间”有3个常用的表达，

①have time for something: 

She realized she would have time for a coffee before her train left. （她觉得火车开之前她还有时间去喝杯咖啡。） 

We don't have to rush. We have all the time in the world (= have plenty of time ) . （不用着急，我们有的是时间。）

②have plenty of time to spare:

Kate had plenty of time to spare for making her own clothes. （凯特有得是时间做她自己的衣服。）

③have time on your hands/time to kill  (= not have enough to do ) 

Now the children have left home, she has too much time on her hands. （现在，孩子们都不住在家里了，她有了很多空闲的时间。） 

With time to kill, he walked to the museum. （还有很多时间，他就走去博物馆。）

3. be out of time: use this to tell someone to stop doing something because there is no more time allowed

备注："be out of time"常用于口语中，尤其常用于电台广播主持人说“节目该结束了”（used on radio and television programs to say that there is no more time available on the program）

例：

I'm sorry, listeners, we have to stop there. We're out of time. （听众朋友，节目结束的时间到了，今天就到这里。）

怎么表达“一段时间的结束”？

1.come to an end: if a long period of time comes to an end , it ends

例：

Autumn came to an end with the first snow. （初雪宣告秋天已经结束。）

2.be over: if a period of time is over , it has ended

例：

The long vacation was almost over, and she hadn't done any of the things she'd planned. （长假已然快要结束，她计划内的事情一件都还没做。）

I think I'm going to lose my temper before this evening is over. （我觉得今晚我要发脾气了。）

3.end:

例：

The school year ends in June. （学年6月份结束。）

Winter was finally ending, and the first flowers of spring had begun to appear. （冬天终于结束了，早春的花开了。）