timezone, dst - difference between Universal (Greenwich mean) time and
A default value of indicates that the default value for the timezone
tunable (420 minutes west of Greenwich, England ) is to be interpreted
as a daylight savings time value.
The value for the tunable should correspond to a defined time zone, and
thus should be at least a multiple of 15 minutes. More commonly the
value will be a multiple of 60 or 30 minutes, corresponding to an hour
or half-hour time zone.
The value of the tunable specifies if the time is with daylight savings
or not. When the value is set to then the system is using daylight
savings time, and if it is set to the system is not.
Any allowed value is equally recommended. However, the chosen value
should correspond to the time zone and daylight saving scheme of the
system site or to a time zone and daylight saving scheme which has
meaning for applications or users.
The tunable is the difference between Greenwich mean time (Universal
Time) and local time, expressed as minutes west of Greenwich, England.
The tunable indicates whether the tunable is to be interpreted as a
standard or daylight savings time value.
These tunables provide a way to convert between Grenwich Mean Time (or
Universal Time) and local time. Although is a tunable, it is not used
to affect the behavior of the system. Rather, it is used to remember
time zone information when the system is rebooted. This information is
returned by under HP-UX extensions. The tunable is independent of
other methods of indicating time zones. For example, gets or sets the
time in either Universal or local time by using the environment vari‐
able. In this case the tunable has no effect. In general, it is best
to refer to the manpages for specific system calls such as and to check
if there is a dependency on the tunable.
Who Is Expected to Change This Tunable?
Restrictions on Changing
Changes to these tunables take effect at the next reboot.
When Should the Value of This Tunable Be Changed?
These tunables may be changed to match the system's geographic time
zone or the time zone of users.
What Other Tunable Values Should Be Changed at the Same Time?
The and tunables should always be set and interpreted as a pair of val‐
All HP-UX kernel tunable parameters are release specific. This parame‐
ter may be removed or have its meaning changed in future releases of
Installation of optional kernel software, from HP or other vendors, may
cause changes to tunable parameter values. After installation, some
tunable parameters may no longer be at the default or recommended val‐
ues. For information about the effects of installation on tunable val‐
ues, consult the documentation for the kernel software being installed.
For information about optional kernel software that was factory
installed on your system, see at
and were developed by HP.
Tunable Kernel Parameters timezone(5)