日内的英文：
one of these day
one of these days
some of these days

This train ticket is valid for three days.
这张车票3日内有效。

This offer must be withdrawn if not accepted within five days.
如五日内不接受，该盘撤消。

Where a judgment is pronounced at the hearing, a copy of the written judgment shall be delivered within 10 days
当庭宣判的，应当在十日内发送判决书

We guarantee you delivery within one day.
我们保证你在一日内收到。

I will be calling you within the next few days to set up an interview.
我会在近日内打电话给您,以安排一次会面。

We offer you firm for three days on fob basis.
我们向您报3日内有效实盘，船上交货价。

When the lease term expires, Party B will return the premises and attached facilities to Party A within days.
租赁期满后，乙方应在日内将房屋交还甲方

Having received a copy of the written appeal, the appellee shall produce a reply within 30 days.
被上诉人在收到上诉状副本后，应当在三十日内提出答辩状。

The people's court shall send a copy of the bill of defence to the plaintiff within five days of receiving it.
人民法院应当在收到答辩状之日起五日内,将答辩状副本发送原告.

Under this circumstance, Party A shall return the deposit in full to Party B within ten (10) days after the termination.
在此情况下，甲方应在本租约终止后十(10)日内将押金全额退还乙方。

One, Taipei, one way.
台北单程票一张。

This one is not a spoof.
这个就不是开玩笑了。

One and one make(s) two.
一加一等于二。

Things go on day by day.
事情逐日进行着。

Day by day the situation is improving.
情况在一天天地好转。

Like this, day after day.
就这样，日复一日。