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How to set timezone so AIX automatically change on Summertime? NT 6
- Thread starter Madz
- Start date
-
6
- #2
Not sure this is what you want? Others may also have set up a TZ variable in their .profile.....but on the whole I believe the TZ variable in the /etc/environment is what you are looking for? Remember cron has to be reset if you do change it....
==================
The /etc/environment file contains variables specifying the basic environment for all
processes. When a new process begins, the exec subroutine makes an array of strings
available that have the form Name=Value. This array of strings is called the
environment. Each name defined by one of the strings is called an environment
variable or shell variable. The exec subroutine allows the entire environment to be set
at one time.
Environment variables are examined when a command starts running. The environment of a process is not changed by altering the /etc/environment file.
Any processes that were started prior to the change to the /etc/environment
file must be restarted if the change is to take effect for those processes. If the TZ
variable is changed, the cron daemon must be restarted, because this variable
is used to determine the current local time.
The variable you are looking for is TZ in this file, I believe
TZ
The time-zone information. The TZ environment variable is set by
the /etc/environment file. The TZ environment variable has the
following format (spaces inserted for readability):
std offset dst offset , rule
The fields within the TZ environment variable are defined as
follows:
std and dst
Designate the standard (std) and summer (dst) time
zones. Only the std value along with the appropriate
offset value is required. If the dst value is not
specified, summer time does not apply. The values
specified may be no less than three and no more
than TZNAME_MAX bytes in length. The length
of the variables corresponds to the %Z field of the
date command; for libc and libbsd,
TZNAME_MAX equals three characters. Any
nonnumeric ASCII characters except the following
may be entered into each field: a leading : (colon), a
, (comma), a - (minus sign), a + (plus sign), or the
ASCII null character.
Note: POSIX 1.0 reserves the leading
: (colon) for an implementation-defined
TZ specification. AIX disallows the
leading colon, selecting CUT0 and
setting the %Z field to a null string.
An example of std and dst format is as follows:
EST5EDT
EST
Specifies Eastern U.S. standard time.
5
Specifies the offset, which is 5 hours behind Coordinated Universal
Time (CUT).
EDT
Specifies the corresponding summer time zone
abbreviation.
Note: See "Time Zones" for a list of time zone names
defined for the system.
offset
Denotes the value added to local time to equal
Coordinated Universal Time (CUT). CUT is the
international time standard that has largely replaced
Greenwich Mean Time. The offset variable has the
following format:
hh:mm:ss
The fields within the offset variable are defined as
follows:
hh
Specifies the dst offset in hours. This field is required. The hh
value can range between the integers -12 and +11. A negative
value indicates the time zone is east of the prime meridian; a
positive value or no value indicates the time zone is west of the
prime meridian.
mm
Specifies the dst offset detailed to the minute. This field is optional.
If the mm value is present, it must be specified between 0 and 59
and preceded by a : (colon).
ss
Specifies the dst offset detailed to the second. The ss field
is optional. If the ss value is present, it must be specified
between 0 and 59 and preceded by a : (colon).
An offset variable must be specified with the std variable. An
offset variable for the dst variable is optional. If no offset is
specified with the dst variable, the system assumes that summer
time is one hour ahead of standard time.
As an example of offset syntax, Zurich is one hour ahead of CUT,
so its offset is -1. Newfoundland is 1.5 hours ahead of eastern
U.S. standard time zones. Its syntax can be stated as any of the
following: 3:30, 03:30, +3:30, or 3:30:00.
rule
The rule variable indicates when to change to and back
from summer time. The rule variable has the following
format:
start/time,end/time
The fields within the rule variable are defined as follows:
start
Specifies the change from standard to summer time.
end
Specifies the return to standard time from summer time.
time
Specifies when the time changes occur within the time zone. For
example, if the time variable is encoded for 2 a.m. then the time
changes when the time zone reaches 2 a.m. on the date specified in
the start variable.
/
Delimits the start date, end date, and time variables.
,
(Comma) Delimits two date and time pairs.
The start and end variables support a syntax for Julian time
(J) and a syntax for leap years (M):
Jn
Mm.n.d
In the J syntax, the n variable has the value of 1 through 365.
Leap days are not counted. In the M syntax, m is the month, n the
week, and d the day of the week starting from day 0 (Sunday).
The rule variable has the same format as the offset variable
except no leading - (minus sign) or + (plus sign) is allowed. The
default of the start variable is 02:00:00 (2 a.m.).
Note: The time zone offsets and time change points
are interrelated and context-dependent. The rule
variable's runtime execution semantics change as a
function of the offsets. For example, if the summer
time zone changes one hour, as in CST6CDT5, (the
default 2 a.m.) summer time changes instantaneously
from 2 a.m. to 3 a.m. CDT. The fall change is from 2
a.m. CDT to 1 a.m. CST. The respective changes for
a time zone of CST6CDT4 are 2 a.m. CST to 4
a.m. CDT and 2 a.m. CDT to 12 a.m. CST.
In an example of the rule variable, if the law changed so that the
Central United States experienced summer time between Julian
129 and Julian 131, the TZ variable would be stated as follows:
TZ=CST6CDT5,J129,J131
In this example, the dates indicated are May 09 and May
11,1993, respectively. (Use the date +%j command to get the
Julian date number.)
In another example, if the time changes were to occur at 2 a.m.
CST and 19:30 CDT, respectively, the variables would be stated
as follows:
TZ=CST6CDT5,J129,J131/19:30
In nonleap years, the fallback time change would be from 19:30
CDT to 18:30 CST on May 11 (1993).
For the leap year (M) syntax, the spring ahead date would be 2
May and the fallback date is 9 May. The variables are stated as
follows:
TZ=CST6CDT5,M5.1.0,M5.2.0
#-)
==================
The /etc/environment file contains variables specifying the basic environment for all
processes. When a new process begins, the exec subroutine makes an array of strings
available that have the form Name=Value. This array of strings is called the
environment. Each name defined by one of the strings is called an environment
variable or shell variable. The exec subroutine allows the entire environment to be set
at one time.
Environment variables are examined when a command starts running. The environment of a process is not changed by altering the /etc/environment file.
Any processes that were started prior to the change to the /etc/environment
file must be restarted if the change is to take effect for those processes. If the TZ
variable is changed, the cron daemon must be restarted, because this variable
is used to determine the current local time.
The variable you are looking for is TZ in this file, I believe
TZ
The time-zone information. The TZ environment variable is set by
the /etc/environment file. The TZ environment variable has the
following format (spaces inserted for readability):
std offset dst offset , rule
The fields within the TZ environment variable are defined as
follows:
std and dst
Designate the standard (std) and summer (dst) time
zones. Only the std value along with the appropriate
offset value is required. If the dst value is not
specified, summer time does not apply. The values
specified may be no less than three and no more
than TZNAME_MAX bytes in length. The length
of the variables corresponds to the %Z field of the
date command; for libc and libbsd,
TZNAME_MAX equals three characters. Any
nonnumeric ASCII characters except the following
may be entered into each field: a leading : (colon), a
, (comma), a - (minus sign), a + (plus sign), or the
ASCII null character.
Note: POSIX 1.0 reserves the leading
: (colon) for an implementation-defined
TZ specification. AIX disallows the
leading colon, selecting CUT0 and
setting the %Z field to a null string.
An example of std and dst format is as follows:
EST5EDT
EST
Specifies Eastern U.S. standard time.
5
Specifies the offset, which is 5 hours behind Coordinated Universal
Time (CUT).
EDT
Specifies the corresponding summer time zone
abbreviation.
Note: See "Time Zones" for a list of time zone names
defined for the system.
offset
Denotes the value added to local time to equal
Coordinated Universal Time (CUT). CUT is the
international time standard that has largely replaced
Greenwich Mean Time. The offset variable has the
following format:
hh:mm:ss
The fields within the offset variable are defined as
follows:
hh
Specifies the dst offset in hours. This field is required. The hh
value can range between the integers -12 and +11. A negative
value indicates the time zone is east of the prime meridian; a
positive value or no value indicates the time zone is west of the
prime meridian.
mm
Specifies the dst offset detailed to the minute. This field is optional.
If the mm value is present, it must be specified between 0 and 59
and preceded by a : (colon).
ss
Specifies the dst offset detailed to the second. The ss field
is optional. If the ss value is present, it must be specified
between 0 and 59 and preceded by a : (colon).
An offset variable must be specified with the std variable. An
offset variable for the dst variable is optional. If no offset is
specified with the dst variable, the system assumes that summer
time is one hour ahead of standard time.
As an example of offset syntax, Zurich is one hour ahead of CUT,
so its offset is -1. Newfoundland is 1.5 hours ahead of eastern
U.S. standard time zones. Its syntax can be stated as any of the
following: 3:30, 03:30, +3:30, or 3:30:00.
rule
The rule variable indicates when to change to and back
from summer time. The rule variable has the following
format:
start/time,end/time
The fields within the rule variable are defined as follows:
start
Specifies the change from standard to summer time.
end
Specifies the return to standard time from summer time.
time
Specifies when the time changes occur within the time zone. For
example, if the time variable is encoded for 2 a.m. then the time
changes when the time zone reaches 2 a.m. on the date specified in
the start variable.
/
Delimits the start date, end date, and time variables.
,
(Comma) Delimits two date and time pairs.
The start and end variables support a syntax for Julian time
(J) and a syntax for leap years (M):
Jn
Mm.n.d
In the J syntax, the n variable has the value of 1 through 365.
Leap days are not counted. In the M syntax, m is the month, n the
week, and d the day of the week starting from day 0 (Sunday).
The rule variable has the same format as the offset variable
except no leading - (minus sign) or + (plus sign) is allowed. The
default of the start variable is 02:00:00 (2 a.m.).
Note: The time zone offsets and time change points
are interrelated and context-dependent. The rule
variable's runtime execution semantics change as a
function of the offsets. For example, if the summer
time zone changes one hour, as in CST6CDT5, (the
default 2 a.m.) summer time changes instantaneously
from 2 a.m. to 3 a.m. CDT. The fall change is from 2
a.m. CDT to 1 a.m. CST. The respective changes for
a time zone of CST6CDT4 are 2 a.m. CST to 4
a.m. CDT and 2 a.m. CDT to 12 a.m. CST.
In an example of the rule variable, if the law changed so that the
Central United States experienced summer time between Julian
129 and Julian 131, the TZ variable would be stated as follows:
TZ=CST6CDT5,J129,J131
In this example, the dates indicated are May 09 and May
11,1993, respectively. (Use the date +%j command to get the
Julian date number.)
In another example, if the time changes were to occur at 2 a.m.
CST and 19:30 CDT, respectively, the variables would be stated
as follows:
TZ=CST6CDT5,J129,J131/19:30
In nonleap years, the fallback time change would be from 19:30
CDT to 18:30 CST on May 11 (1993).
For the leap year (M) syntax, the spring ahead date would be 2
May and the fallback date is 9 May. The variables are stated as
follows:
TZ=CST6CDT5,M5.1.0,M5.2.0
#-)
aixqueen
:-Q
belated thanks for excellent TZ response which ive just found ... was trying to decypher :
GMT0BST, M3.5.0, M10.5.0
would you consider putting your reply in faq ? which is where i first looked
Best of Irish Luck, David.
djwilkes@hotmail.com
:-Q
belated thanks for excellent TZ response which ive just found ... was trying to decypher :
GMT0BST, M3.5.0, M10.5.0
would you consider putting your reply in faq ? which is where i first looked
Best of Irish Luck, David.
djwilkes@hotmail.com
I like this man already. Mike- Status
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