






;; [15] [[軍隊]]における[[日時]]一般は[[軍用時]]を参照。

* 

[FIG(quote)[ [11] [[ARINC 424-17]] 125ページ

> 5.178 Time Zone
> Definition/Description: The standard time zone system is
based on the division of world into 24 zones, each of 15
degrees longitude. The “zero” time zone is entered at
Greenwich meridian with longitudes 7 degrees, 30 minutes
West and 7 degrees, 30 minutes east, and there is no
difference in the standard time of this time zone and
Greenwich Mean Time. Time zones are designated by
letters of the alphabet by which the standard time of each
zone differs from that at Greenwich.
> Source/Content: Time zones will be derived from official
Time Zone Charts of the World. The first character of the
field indicates the time zone observed by the airport. Time
zones are indicated by a letter of the alphabet according to
the following table:
>
,*Field Cont,*Diff to Zulu time,*Lat/long Boundaries
,Z,0,W007 30/E007 30
,A,-1,E007 30/E022 30
,B,-2,E022 30/E037 30
,C,-3,E037 30/E052 30
,D,-4,E052 30/E067 30
,E,-5,E067 30/E082 30
,F,-6,E082 30/E097 30
,G,-7,E097 30/E112 30
,H,-8,E112 30/E127 30
,I,-9,E127 30/E142 30
,K,-10,E142 30/E157 30
,L,-11,E157 30/E172 30
,M,-12,E172 30/180 00
,N,+1,W007 30/W022 30
,O,+2,W022 30/W037 30
,P,+3,W037 30/W052 30
,Q,+4,W052 30/W067 30
,R,+5,W067 30/W082 30
,S,+6,W082 30/W097 30
,T,+7,W097 30/W112 30
,U,+8,W112 30/W127 30
,V,+9,W127 30/W142 30
,W,+10,W142 30/W157 30
,X,+11,W157 30/W172 30
,Y,+12,W172 30/180 00
> The second and third characters indicate, in minutes, that
the time observed by the airport/heliport must be adjusted
from the hour by the number of minutes indicated.
> Used On: Airport and Heliport records
> Length: 3 characters
> Character Type: Alpha/numeric
> Examples: India falls in the “E” (-5) and “F” (-6)
time zones, however, the time zone
observed in all of India is “E30” (-5
hours and 30 minutes). For any country
falling into the “M” or “Y” time zone and
observing a time equal to the next greater
time zone, the adjustment of 1 hour will
be indicated by “60” in the second and
third positions. 
]FIG]

* 文脈

[16] [CODE[TypeDesignator]]

* メモ

[1] [CITE@en[List of military time zones - Wikipedia, the free encyclopedia]]
( ([TIME[2014-05-03 22:26:04 +09:00]] 版))
<http://en.wikipedia.org/wiki/List_of_military_time_zones>

[2] [[RFC 822の日付形式]]は[[米軍時間帯]]も認めていましたが、 [[RFC 822]]
の記述が誤っていたため、 [[RFC 1123]] は意味を成さないと述べています。
[[RFC 2822の日付形式]]は[[米軍時間帯]]の使用を認めていません。


[3] [CITE@en[Nautical time - Wikipedia, the free encyclopedia]]
( ([TIME[2014-05-11 01:03:11 +09:00]] 版))
<http://en.wikipedia.org/wiki/Nautical_time>

[4] [CITE@en[Anglo-French Conference on Time-keeping at Sea - Wikipedia, the free encyclopedia]]
([TIME[2016-08-07 23:08:34 +09:00]])
<https://en.wikipedia.org/wiki/Anglo-French_Conference_on_Time-keeping_at_Sea>

[5] [CITE@ja[24時制 - Wikipedia]]
( ([TIME[2017-02-27 21:43:54 +09:00]]))
<https://ja.wikipedia.org/wiki/24%E6%99%82%E5%88%B6>

[FIG(quote)[
[FIGCAPTION[
[6] [CITE@en[RFC 822 - STANDARD FOR THE FORMAT OF ARPA INTERNET TEXT MESSAGES]]
([TIME[2017-05-07 07:58:45 +09:00]])
<https://tools.ietf.org/html/rfc822>
]FIGCAPTION]

>  "Z" is Universal Time.
>      "A" indicates one hour earlier, and "M" indicates 12  hours  ear-
>      lier;  "N"  is  one  hour  later, and "Y" is 12 hours later.  The
>      letter "J" is not used.  The other remaining two forms are  taken
>      from ANSI standard X3.51-1975.  One allows explicit indication of
>      the amount of offset from UT; the other uses  common  3-character
>      strings for indicating time zones in North America.
>      ANSI.  "Representations of Universal Time, Local  Time  Differen-
>         tials,  and United States Time Zone References for Information
>         Interchange," X3.51-1975.  American National Standards  Insti-
>         tute:  New York (1975).

]FIG]


[FIG(quote)[
[FIGCAPTION[
[7] [CITE@en[RFC 2822 - Internet Message Format]]
([TIME[2017-05-07 16:18:47 +09:00]])
<https://tools.ietf.org/html/rfc2822#page-32>
]FIGCAPTION]

> 
>    The 1 character military time zones were defined in a non-standard
>    way in '''['''RFC822''']''' and are therefore unpredictable in their meaning.
>    The original definitions of the military zones "A" through "I" are
>    equivalent to "+0100" through "+0900" respectively; "K", "L", and "M"
>    are equivalent to  "+1000", "+1100", and "+1200" respectively; "N"
>    through "Y" are equivalent to "-0100" through "-1200" respectively;
>    and "Z" is equivalent to "+0000".  However, because of the error in
>    '''['''RFC822''']''', they SHOULD all be considered equivalent to "-0000" unless
>    there is out-of-band information confirming their meaning.
> 

]FIG]


[FIG(quote)[
[FIGCAPTION[
[8] [CITE@en[RFC 5322 - Internet Message Format]]
([TIME[2017-05-07 16:14:34 +09:00]])
<https://tools.ietf.org/html/rfc5322#page-34>
]FIGCAPTION]

> 
>    The 1 character military time zones were defined in a non-standard
>    way in '''['''RFC0822''']''' and are therefore unpredictable in their meaning.
>    The original definitions of the military zones "A" through "I" are
>    equivalent to "+0100" through "+0900", respectively; "K", "L", and
>    "M" are equivalent to "+1000", "+1100", and "+1200", respectively;
>    "N" through "Y" are equivalent to "-0100" through "-1200".
>    respectively; and "Z" is equivalent to "+0000".  However, because of
>    the error in '''['''RFC0822''']''', they SHOULD all be considered equivalent to
>    "-0000" unless there is out-of-band information confirming their
>    meaning.

]FIG]


[FIG(quote)[
[FIGCAPTION[
[9] [CITE@en[RFC 733 - Standard for the format of ARPA network text messages]]
([TIME[2017-05-14 17:07:36 +09:00]])
<https://tools.ietf.org/html/rfc733>
]FIGCAPTION]

> The  military
> standard   uses  a  single  character  for  each  zone.   "Z"  is
> Greenwhich Mean Time; "A" indicates one  hour  earlier,  and  "M"
> indicates  12 hours earlier; "N" is one hour later, and "Y" is 12
> hours later.  The letter "J" is not used.

]FIG]

[10] [[インターネットメール]]には [[RFC 733]] で導入されたようで、
それ以前にはありません。

[FIG(quote)[
[FIGCAPTION[
[12] [CITE@ja[「時刻は i か? z か?」 - あれこれdiary]]
([TIME[2018-06-10 15:46:25 +09:00]])
<http://retcapt1501.hatenablog.com/entry/2018/01/27/202108>
]FIGCAPTION]

> ですから、日本標準時での時刻表記は、例えば午前7時45分なら「0745i」と時刻の後ろに、時刻帯符号の「i」を付け、「まるななよんご いんでぃあ」と読みます。 [SNIP[]] 海上自衛隊の、特にオペレーション部門や情報部門では、時刻情報が入ったときには、「それは日本標準時なのか世界標準時なのか」を必ず確認します。そのとき、具体的な言葉としては、記事タイトルにあるような「インディアかズールーか」という質問になるわけです。

]FIG]


[FIG(quote)[
[FIGCAPTION[
[13] [CITE@ja[第26回:GMT(グリニッジ標準時)で動く米国海軍 « 個人を本気にさせる研修ならイコア]]
([TIME[2018-06-10 15:54:40 +09:00]])
<http://www.ecore-i.co.jp/ecore-room/er-navy-manage/ernm26>
]FIGCAPTION]

> 暗号を使用したテレグラム(電報)の冒頭に、発信日時というものがつきますが、
> 211200Z NOV 2011」ということで、時刻の後に時刻帯を表す「Z」の文字がつい
> てきます。「Z」はGMTであることを表し「i」はJSTであることを表しています。

]FIG]


[14] [CITE@ja[自衛隊宮城地方協力本部@公式ですよ☆さんのツイート: "1200i ヒトフタマルマル(インディア) グリニッジ標準時刻(東経0度)をZとし、15度(1時間)進む毎にアルファベットを付与する。日本は東経135度なので135÷15=9となり、9番目のアルファベットiが135度の時間帯(日本)となる。 機会があったら艦艇広報で探して見てねw"]]
([TIME[2018-06-10 16:00:32 +09:00]])
<https://twitter.com/miyagipco/status/433445552122904576>

[17] [CITE@ja-JP[異常気象報告 昭和26年 第3号 (昭和26年(1951)1月-5月の熱帯性の低気圧活動状況)]], [[中央気象台]], [TIME[1951]], [TIME[2023-01-17T10:48:16.000Z]], [TIME[2023-02-16T06:16:26.274Z]] <https://dl.ndl.go.jp/pid/1372799/1/32> (要登録)