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.

"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).

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.

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.

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.

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。 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。

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。