英文中每个月的名称有何来历？

The first month in the calendar named after a real person, July was named in honour of Julius Caesar after his death in 44 BC, July being the month of his birth. Before it was renamed, the month was known as Quintilis (borrowed into English as Quintile), which means ‘fifth’. If you’ve been counting, you’ll know that July isn’t the fifth month: we’ll come on to that when we reach September and October.
July是日历中第一个以真实的人物命名的月份，七月的命名是为了纪念尤里乌斯•凯撒（Julius Caesar）。公元前44年，凯撒大帝去世，七月是他出生的月份。在更名之前，这个月叫做“Quintilis”（英语则为“Quintile”），意为“第五”。如果你数过了的话，你会发现七月并不是第五个月：这一点在说到九月和十月的时候我们会做出解释。

August 八月

Following suit, in 8 BC, the month Sextilis (‘sixth’) was renamed after Augustus, the first Roman emperor, who had died six years earlier. Augustus himself was given this title when he became emperor, having previously been known as Octavian. It came from the Latin augustus meaning ‘consecrated, venerable’ which gave rise to the English adjective august, ‘respected and impressive’.
同样地，在公元前8年，“Sextilis” (‘sixth’)这个月以古罗马第一位帝王奥古斯都（Augustus）来命名，他本人早于六年前去世。奥古斯都是他在成为帝王之时为自己改的名字，在这之前，他叫奥克塔维安（Octavian）。这个词来源于拉丁语“augustus”，意为“神圣的、值得尊敬的”，由此，august在做形容词时有“值得尊敬的”的意思。

September 九月

September follows on from Quinitlis and Sextilis, in that it comes from the Latin septem, ‘seven’. As with those (and the rest of the calendar), the numbering is a bit off now: September was originally the seventh month in an ancient Roman ten-month calendar, which started with March.
“September”排在“Quinitlis”和“Sextilis”之后，是因为它来源于拉丁语“septem”，在这里是指第七个月。到这里，这些月份（以及日历中其它月份）的排序方式就有点混乱了：在古罗马的十月制日历中，September是第七个月份，那个日历是从March开始的。

October 十月

More of the same: octo is the Latin for ‘eight’, for that ten month calendar. Two months were added to the end of the calendar year around 713 BC, and the beginning of the year was moved to 1 January in 153 BC.
同理，“octo”在拉丁语中是八的意思，因此在十月历中，它是指第八个月。在公元前713年左右，日历年的年底又加了两个月，公元前153年将一月一日作为一年的开始。

November 十一月

The pattern continues: November comes from novem, ‘nine’. November is also, we’re afraid, used ‘with allusion to November’s position at the end of the year, and to the characteristic greyness, gloominess, etc., associated with it in the northern hemisphere’. The earliest known example of this allusive use comes from Jane Austen’s posthumously published novel Persuasion.
还是相同的规律：“November”来源于拉丁语“novem”，即第九个月。我们认为“Novembe”同样也“暗指其处于年末，用以表示灰暗、阴郁等，与北半球相关”。这种暗指性的用法最早见于简-奥斯汀（Jane Austen）去世后出版的《劝导》（Persuasion）一书中。

December 十二月

And we finish off the year with December, from decem, ‘ten’. The month also comes with a brace of adjectives: Decemberish and Decemberly, the latter of which can also be used as an adverb. And there you have it: a whole calendar year of etymologies to see you through the whole of 2016.
我们以“December”作为一年的终结，它来源于“decem”，这里指第十个月。这个词还有两个形容词形式：“Decemberish”和“Decemberly”，后者还可用作副词。以上就是可以伴你度过2016年的所有月份典故来源了。