1、Installation of the new system will take several days.新系统的安装需要几天时间。

2、It's been quite a day， one way and another.从几方面看，这是不寻常的一天。

3、It's been one of those days!这一天真倒霉！

4、I would imagine the job will take about two days.我猜想这工作大概需要两天左右的时间吧。