D-Day History

In the military, D-Day is the day on which a combat attack or operation is to be initiated. The best known D-Day is during World War II, on June 6, 1944—the day of the Normandy landings—initiating the Western Allied effort to liberate mainland Europe from Nazi. However, many other invasions and operations had a designated D-Day, both before and after that operation.

The terms D-Day and H-Hour are used for the day and hour on which a combat attack or operation is to be initiated. They designate the day and hour of the operation when the day and hour have not yet been determined, or where secrecy is essential. For a given operation, the same D-Day and H-Hour apply for all units participating in it. When used in combination with numbers, and plus or minus signs, these terms indicate the point of time preceding or following a specific action. Thus, H−3 means 3 hours before H-Hour, and D+3 means 3 days after D-Day. (By extension, H+75 minutes is used for H-Hour plus 1 hour and 15 minutes.) Planning papers for large-scale operations are made up in detail long before specific dates are set. Thus, orders are issued for the various steps to be carried out on the D-Day or H-Hour minus or plus a certain number of days, hours, or minutes. At the appropriate time, a subsequent order is issued that states the actual day and times.

Other days such as A-Day (Battle of Leyte), L-Day (Battle of Okinawa) etc. have different meanings for the military.

Other languages have terms equivalent to D-Day such as "Hari H" (Indonesian),Час Ч (Russian), Dagen D[citation needed] (Swedish), Dan D (Slovenian), E eguna (Basque), Jour J (French), Lá L (Irish), Tag X (German), and Ziua-Z (Romanian). The initial D in D-Day has been given various meanings in the past, while more recently it has obtained the connotation of "Day" itself, thereby creating the phrase "Day-Day", or "Day of Days".

在军事上，D日是在这一天战斗攻击或操作将被启动。最著名的D日是在二战期间，于6月6日，诺曼底登陆，引发西方盟军的努力，从纳粹解放欧洲大陆的1944年的一天。然而，许多其他的入侵和操作有一个指定的D日之前和该操作后。

术语D日和H小时被用于日和小时在其上战斗的攻击，或者操作将启动。它们指定操作的日期和小时的时日和小时尚未确定，或者其中保密是必不可少的。对于给定的操作，同样的D日和H小时申请参加它的所有单位。当与数字和加号或减号组合使用，这些术语表示时间之前或之后的特定作用点。因此，H-3是指H-小时前3个小时，与D + 3装置3天D日之后。 （通过扩展，H + 75分钟内使用H-小时加1小时15分钟。）规划的论文进行大规模的操作进行了详细具体日期设置没过多久组成。因此，订单发出要进行的各种步骤的D日或H小时减去或加上一定的天数，小时或分钟。在适当的时候，后续的订单发出，指出实际日期和时间。

如A-日（莱特战役）其他日子，L-日（冲绳岛战役）等对军队不同的含义。

其他语言有条款相当于D-日，如“哈日H”（印尼），ЧасЧ（俄罗斯），达恩D [来源请求]（瑞典），丹·D（斯洛文尼亚），E eguna（巴斯克），怨妇J（下法国），LA L（爱尔兰），标签X（德国），以及Ziua-Z（罗马尼亚）。在D日的头文字D被赋予在过去的各种含义，而最近已获得“天”本身的内涵，从而创造了那句“日日”或“日天数”。