This meeting should take about two hours.
这次会议大约需要两个小时。
This meeting shouldn't take that long.
这次会议不会持续那么长时间的。
This meeting is due to finish at 3:00.
本次会议预计在三点结束。
I want to finish this meeting in a hour.

我想在一个小时内结束本次会议。

We will have a coffee break every 50 minutes.
我们每50分钟会有一次茶歇。
We will have a twenty-minute break after discussing all the items on the agenda.
在讨论完会议议程上的所有事项之后，我们将休息20分钟。
A 40-minute lunch break will be given to you if we cannot finish our discussion by lunch time.
如果到了午餐时间我们还没有讨论完，将给各位40分钟的时间吃午餐。