Technical data

Setting System Time
6.2 Setting Time Zone Information on OpenVMS Alpha Version 7.3 and Later
If you answer Yes or press Return to accept the default, time zone information is
set. This includes:
• The following system logical names, which are set with the time zone
information:
• SYS$LOCALTIME
• SYS$POSIXRULES
• SYS$TIMEZONE_DAYLIGHT_SAVING
• SYS$TIMEZONE_NAME
• SYS$TIMEZONE_RULE
• The following files, which are written so that time zone information can be
reset when the system is rebooted:
• [VMS$COMMON.SYSEXE]SYS$TIMEZONE_SRC.DAT
• [VMS$COMMON.SYS$STARTUP]TDF$UTC_STARTUP.COM
The system next displays the TDFs for standard and daylight saving time that
correspond to the time zone you have selected, and information about the TDF.
For example:
Default Time Differential Factor for standard time is -5:00.
Default Time Differential Factor for daylight saving time is -4:00.
The Time Differential Factor (TDF) is the difference between your
system time and Coordinated Universal Time (UTC). UTC is similar
in most repects to Greenwich Mean Time (GMT).
The TDF is expressed as hours and minutes, and should be entered
in the hh:mm format. TDFs for the Americas will be negative
(-3:00, -4:00, etc.); TDFs for Europe, Africa, Asia and Australia
will be positive (1:00, 2:00, etc.).
Note that the system displays daylight saving time information only for time
zones that use daylight saving time. If the time zone you selected uses daylight
saving time, you must indicate whether daylight saving time is or is not currently
in effect. Answer Y (Yes) or N (No) when you are prompted. For example:
Is Daylight Savings time in effect? Y
You are then prompted to enter the TDF. A default, based on your time zone
and daylight saving time information, is provided. In the following example the
default is -4:00. Compaq recommends that you press Return to accept the default.
Enter the Time Differential Factor [-4:00]:
Return
This results in the following (or similar) display:
If this is a seasonal time change, it may also be necessary to
modify the system time. Generally, seasonal time changes result
in adding 1:00 hour, or adding -1:00 hour to the system time.
When you are prompted, enter Yes or No.
Do you wish to modify the local system time [N]: Yes
6–8 Setting System Time