When we use it this way, it means " not later than" .

用作这种含义的时候，它的意思是" 不迟于。

I only take a short lunch break and try to finish not later than 7 pm.

我午休时间很短，尽量不晚于晚上 7 点结束工作。

Completed entry forms should arrive not later than 31st July.

【later】填写好的参赛表格须于 7 月 31 日前递交。

Arabella went, Jude requesting her to be home not later than by the seven o'clock train.

阿拉贝拉去了， 裘德要求她不晚于七点钟的火车回家。

She had simply skipped dinner and left a message for her mother that she would be back not later than seven.

她干脆不吃晚饭，给妈妈留言说她最晚七点回来。

" I was promised in St. Petersburg that the news of this woman's fate would be sent to this place not later than this month" .

“我在圣彼得堡得到承诺，这个女人的命运的消息最迟会在这个月传到这个地方”。

Tankers built before that date had to be fitted with a similar arrangement not later than 1 January 1999. Regulation 22 is aimed at improving navigation bridge visibility.

在此日期之前建造的油轮必须在 1999 年 1 月 1 日之前安装类似的装置。第 22 条旨在提高驾驶台能见度。

You'll also sometimes see it spelled this way in song lyrics, which are, of course, types of poems. " By" (by) means any time before, but not later than.

有时您还会在歌词中看到这种拼写方式， 当然，这是诗歌的类型。 “由” （by）表示之前的任何时间，但不迟于。