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The OpenVMS Frequently Asked Questions (FAQ)


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4.4.1 Creating, Updating and Managing Timezone Definitions?



FOne issue with the UTC implementation on OpenVMS is the behaviour of CDfunctions and other programs that use SYS$TIMEZONE_RULE; the OpenVMSEmechanism assumes all control over the timezone and the daylight timeDswitchover. This allows calculation of the time by the C library andvarious applications.

CThis can be incompatible with a system or application that requiresCmanual modifications to the DST or TDF settings, or that requires aFlocal or customized timezone definition. For such a site to ensure theEtimekeeping is correct, the site must provide procedure that sets the@local time and the TDF when the SYS$TIMEZONE_RULE says to do it.

FIf a site requires a non-standard time switch-over, as in coordinatingGwith a shift change or due to changes in the local or regional timezone$rules, the site will need to use the.zic compiler to create a custom timezone rule.

DAdditionally, applications may need to have special actions taken or?actions queued just before the time change takes effect. If theDapplication source code is available, one of the best ways to handleEthis is via the TDF and time-change notification events available via the OpenVMS sys$set_system_event system service.

CFor information on zic and related tools used to manage the OpenVMSATimezone database, please see the HP C Run-time Library Utilities?Reference Manual---though the title would imply otherwise, thisCparticular manual is part of the OpenVMS documentation set, and notGpart of the HP C (formerly Compaq C, formerly DEC C) documentation set.

bFor related information, see Section 4.4.1.1.Z

4.4.1.1 Customizing or Updating your TDF (Timezone) Setting?



FIndividual, local, and regional differences on the use (or the lack ofFuse) of Daylight Saving Time (DST) are quite common, as are occasionalFregulatory changes to the particular applicable regional DST settings.F(eg: The United States Government is expecting to change its DST ruleswstarting 1-Mar-2007; please see Section 4.4.1.2 for details.)

@If you need to add, modify or remove DST rules for your area, orGotherwise alter the rules for your local area, you will probably end upAcreating a variation to an existing timezone rule, or potentiallyFsimply downloading a new set of DST rules. This requirement can arise,>for instance, if your local region changes its timezone rules.

BThe necessary zone line to add for support of the hypothetical new>WhereEverLand timezone will probably look something like this:

 

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?# Zone  NAME            GMTOFF  RULES/SAVE      FORMAT  [UNTIL]9Zone    WhereEver       2:00    -               WhereEver




@The OpenVMS source files for the timezone rules are stored here:

 

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(SYS$COMMON:[SYS$ZONEINFO.SYSTEM.SOURCES]




@You'll then want to use the zic compiler to compile your own newDtimezone definition, or to compile a new set of timezone definitions:that have been freshly downloaded from a published source.

DThe zic compiler is documented in the OpenVMS Documentation Set, andDspecifically in the HP C Run-Time Library Reference Manual. (DespiteDthe name of this manual, it is part of the OpenVMS documentation setand not of the C manuals.)

?Once you have created and compiled a new timezone rule (or haveDdownloaded and have compiled a whole new set of timezone rules), use"the SYS$MANAGER:UTC$TIME_SETUP.COMCto select the new timezone if necessary---with V7.3 and later, thisCtool will automically notice the new timezone and will offer it, on@earlier releases, you may/will have to hack the code of the toolFsomewhat to allow it to present the new timezone rule. (If an existingBtimezone rule is simply changing, you don't need this re-selectionstep.)



/  
Note

{As mentioned in Section 4.4.2, please don't modify or redefine the TZ4logical name (found on older configurations), or theSYS$TIMEZONE_NAME logical name,Gor any other time- or timezone-related logical names directly yourself.ARather, please use the zic compiler and/or the UTC$TIME_SETUP.COMprocedure.


GFor various published timezone rules or updated to same, see the tar.gz4files (these are gzipped tar archives) available at:

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  • ftp://elsie.nci.nih.gov/pub/


DThese are gzipped tar archives, and are the pubished source used forDthe OpenVMS timezone rules on OpenVMS V7.3 and later, and within theApredecessor C run-time environment timezone support used on olderDOpenVMS releases. You'll need to first gunzip and then use vmstar to/unpack and access the contents of the archives.

FThe published timezone rules include the effective date ranges for theDindividual rules, so you can reload your rules prior to a particular@set of new rules becoming effective. The effective dates for theAparticular timezone rules are additionally necessary to allow theGappropriate translation of older dates and times within the appropriate9historical context of the particular date and time value.

aFor related information, see Section 4.4.1.X

4.4.1.2 US Daylight Time Changes Starting 1-Mar-2007?



EThe United States Federal Government is presently expecting to change'its DST rules starting with 1-Mar-2007.

EAs amended, US daylight time will be increased to run from the secondESunday in March through the first Sunday of October, inclusive. OtherGcountries, US local political geographies and businesses may or may not4follow suite and implement these changes, obviously.

GFor further regulatory details, see the US Uniform Time Act of 1966 (15<U.S.C 260a(a)), as amended by the Energy Policy Act of 2005.

GFor details on how to create, customize or to download new rules and torupdate your local timezone rules, please see Section 4.4.1.1.N

4.4.2 Timezones and Time-related Logical Names?



DVarious logical names are used to manage time and timezones, and you>should avoid direct modification of these logical names as theGimplementations are subtle and quick to change. As discussed in sectionzSection 4.4.3, you will want to use the following command procedure to#maintain the time and the timezone:

    $
  • SYS$MANAGER:UTC$TIME_SETUP.COM


DIf you want to venture into uncharted territories and modify the TDFEused within older releases of TCP/IP Services---within releases priorBV5.0---you can attempt to use the following undocumented commands:

 

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0SET TIME/DIFF=[positive or negative TDF integer]
GENERATE TIME




/to reset the value of the logical name UCX$TDF.

#Prior to OpenVMS V7.3, the command:

 

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)$ SETTZ :== $SYS$SYSTEM:DTSS$SET_TIMEZONE$ SETTZ MODIFY




Gcan be used to modify the settings of the SYS$TIMEZONE_DAYLIGHT_SAVING,ESYS$TIMEZONE_DIFFERENTIAL, and SYS$TIMEZONE_NAME system logical namesbased on the SYS$TIMEZONE_RULE.

CThe following are other TDF-related logical names used/available onFOpenVMS systems, with typical daylight time and standard time settings&for the US Eastern Time (ET) timezone.

 

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$daylight_time:+$ DEFINE/SYSTEM/EXECUTIVE MAIL$TIMEZONE EDT4$ DEFINE/SYSTEM/EXECUTIVE NOTES$TIMEZONE "-0400 EDT"G$ DEFINE/SYSTEM/EXECUTIVE LISP$DAYLIGHT_SAVING_TIME_P true  ! Not 'EDT'8$ DEFINE/SYSTEM/EXECUTIVE LISP$TIME_ZONE 05   ! Constant$$standard_time:+$ DEFINE/SYSTEM/EXECUTIVE MAIL$TIMEZONE EST4$ DEFINE/SYSTEM/EXECUTIVE NOTES$TIMEZONE "-0500 EST"G$ DEFINE/SYSTEM/EXECUTIVE LISP$DAYLIGHT_SAVING_TIME_P false ! Not 'EST'8$ DEFINE/SYSTEM/EXECUTIVE LISP$TIME_ZONE 05   ! Constant$5$ DEFINE/SYSTEM/EXECUTIVE UCX$NFS_TIME_DIFFERENTIAL -B    'f$integer(f$element(0," ",f$logical("notes$timezone"))/-100)'




@For information on modifying these timezone logical names and onemanaging the timezone rules, see Section 4.4.1.O

4.4.3 How to troubleshoot TDF problems on OpenVMS?



DThis is an OpenVMS Alpha system prior to V7.0 and the startup is notinvoking the procedure:

 

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SYS$MANAGER:UTC$TIME_SETUP.COM




FThis is an OpenVMS system prior to V6.0, where there is no OpenVMS TDFnor UTC available.

AThe version of the application does not use the OpenVMS TDF. ThisEincludes TCP/IP Services prior to V5.0, applications using HP C built<on or targeting OpenVMS prior to V7.0, and systems using the@DECnet-Plus DTSS mechanisms prior to the release associated with@OpenVMS V7.3. (DCE DTS TDF management details to be determined.)

?If you should find either of the following two timezone-related0database files located in SYS$SPECIFIC:[SYSEXE]:

    +
  • SYS$SPECIFIC:[SYSEXE]SYS$TIMEZONE.DAT/
  • SYS$SPECIFIC:[SYSEXE]SYS$TIMEZONE_SRC.DAT


EThese two files are in an erroneous location and must be recreated inthe correct directory:

 

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SYS$COMMON:[SYSEXE]




If the DCL command:

 

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($ DIRECTORY SYS$SYSTEM:SYS$TIMEZONE*.DAT




Dshows these files in SYS$SPECIFIC:[SYSEXE], then delete them and use0SYS$MANAGER:UTC$TIME_SETUP.COM to recreate them.

/On OpenVMS versions prior to V7.3, if the file:

 

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"$ SYS$STARTUP:DTSS$UTC_STARTUP.COM




7is present on your system, then you may need to invoke:

 

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,$ @SYS$UPDATE:DTSS$INSTALL_TIMEZONE_RULE.COM




=to recreate the timezone files correctly. Invoke this command@immediately after [re]executing SYS$MANAGER:UTC$TIME_SETUP.COM.)

CIf SYS$UPDATE:DTSS$INSTALL_TIMEZONE_RULE.COM is not present on your<system, then you may need to execute the following commands:

 

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)$ DELETE SYS$STARTUP:DTSS$UTC_STARTUP.COM)$ DEASSIGN/SYSTEM/EXEC SYS$TIMEZONE_RULE.




BIf your system time is being reported as being off by one hour (oruwhatever the local DST change), please see sections Section 4.7,Section 4.4 and Section 10.22.1.t

4.5 Why does the SET TIME command fail? Help managing DTSS?



DIf you try to set the system time with the SET TIME command, and seeone of the following messages:

 

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#%SET-E-NOTSET, error modifying time0-SYSTEM-F-IVSSRQ, invalid system service request#%SET-E-NOTSET, error modifying time+-SYSTEM-E-TIMENOTSET, time service enabled;.1  enter a time service command to update the timeo

a


aCThis occurs if the time on the local system is controlled by a timeuCservice software, for example the distributed time service software"A(DTSS) provided as part of the DECnet-Plus installation. The DTSS Asoftware communicates with one or more time servers to obtain the=current time. It entirely controls the local system time (fori;DECnet-Plus, there is a process named DTSS$CLERK for this);"@therefore, the usage of the SET TIME command (and the underlying$$SETTIM system service) is disabled.

bFThe first message is displayed on systems running DECnet-Plus V6.1 andDearlier. On systems with newer DECnet-Plus software, the second (and#more informative) message is given.>

cDYou shouldn't have to change the time manually - you should be doingBthis through the time server - but if you insist... you'll have toshutdown DTSS:

a 

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$ RUN SYS$SYSTEM:NCLDISABLE DTSSDELETE DTSSo




eEThis will shutdown DTSS$CLERK. You may then change the system time as)usual. To restart the DTSS software, typei

e 
v
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$ @SYS$STARTUP:DTSS$STARTUPa

a


tCYou will need a number of privileges to ussue this command, and youa@must also be granted the NET$MANAGE identifer to shutdown and to restart DTSS.

mGIf you wish to "permanently" disable DTSS on a system runningsCDECnet-Plus, the above NCL sequence must be performed each time theiFsystem is bootstrapped. (On DECnet-Plus V7.3 and later, you can define!the logical name NET$DISABLE_DTSSxF to disable the DTSS startup. This logical name must be defined in the" command procedure SYLOGICALS.COM,G as this logical name must be present and defined sufficiently early ino; the OpenVMS system bootstrap sequence for it to function.)i

CIf DTSS is running and no time servers are configured, you can (and 6will) see the following messages at regular intervals:

 
u
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8%%%%%%%%%%%  OPCOM   2-SEP-1999 19:41:20.29  %%%%%%%%%%%"Message from user SYSTEM on UNHEDI>Event: Too Few Servers Detected from: Node LOCAL:.mynode DTSS,-        at: 1999-09-02-19:41:20.296-04:00Iinfs        Number Detected=0,        Number Required=1m7        eventUid   5FA70F4F-616E-11D3-A80E-08002BBEDB0Fj7        entityUid  DE9E97DE-6135-11D3-8004-AA000400BD1Bt7        streamUid  D6513A46-6135-11D3-8003-AA000400BD1Bd

h


aGYou can either configure the appropriate number of time servers, or youGcan disable DTSS, or you can ignore it and (if OPCOM is set to write toz$the log via via the logical names inESYLOGICALS.COM/SYLOGICALS.TEMPLATE) clean out OPERATOR.LOG regularly.l

s:You can also simply disable the display of these messages:

t 
E
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$ run sys$system:ncl5block event dispatcher outbound stream local_stream -.    global filter -m,    ((Node, DTSS), Too Few Servers Detected)

t


aDIf you wish to disable the automatic TDF adjustment for the daylightEtime switch-over (on OpenVMS versions prior to V7.3), you can use theacommand:

a 
i
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$ run sys$system:ncl%set dtss automatic TDF change = falseg

s


dEor alternatively, you can set the local timezone to one that does notl0include the automatic daylight time change-over.

l=OpenVMS V7.3 and later simplify time and timezone management.aw

4.6 Setting time on AlphaServer ES47, ES80, GS1280 console?

w

ATo set the base system time on an member of the AlphaServer ES47, EAlphaServer ES80 or AlphaServer GS1280 series system family, you mustMDaccess the Platform Management Utility (PMU). The PMU is implementedCwithin this family of related AlphaServer systems, and is part of a Blayer providing services beyond those of the traditional Alpha SRMEconsole layer, and within a layer architecturally implemented beneathi>the SRM console. In particular, the PMU and related management7components are used to provide services across multiplefF vPars or nPars partitions. In particular, the SRM obtains and managesG the local system time on these systems as a delta time offset from theCA underlying base system time. Neither the SRM console nor OpenVMSaG directly accesses nor alters the underlying base system time nor other)- information maintained within the PMU layer.n

zFThe PMU uses the System Management components, centrally including theDBackplane Manager (MBM) module found in each drawer, user interface,GPCI and CPU management components, and the interconnections among these,Bprovided by the private system management LAN. When the system has@power applied and the main breakers are on, the MBMs are active.

lFThe PMU offers a command line interface for a serial communications orGtelnet connection and allows command and control of the MBM, and of thep<server. The PMU and the MBM system management components are$responsible for the following tasks:

    C
  • Show the system configuration and provide the basic debugging> capabilityD
  • Initiate the firmware update or load the test firmware version=
  • Power on or off, halt, or reset the system or partition3
  • The system partitioning and cabling functions>D
  • Displays of the health of hardware environment, including suchF constructs as fans, power supplies and environmental and temperature values.=$
  • Remote server management tasks/
  • The connection to the virtual SRM consolel(
  • Set and show the base system time.
u

zBYou can use the MBM commands SHOW TIME and SET TIME to view and toEmanipulate the base system time. The delta time value for the primaryiCMBM will be indicated, and it is this value in conjunction with theiDbase time that is used to generate the time available to OpenVMS viaGthe SRM console. If you issue a SET TIME=time command from OpenVMS, the Gdelta time will change, but not the MBM base system time. If you changesFthe MBM base system time, the calculated time available to OpenVMS viaFthe SRM console(s) will change. (Resetting the base time thus involves=changing the base system time, and then issuing SET TIME=timetGcommand(s) to each of the OpenVMS vPars or nPars environments to adjusteEthe respective delta time values.) Rebooting, resetting or issuing anr(MBM SET TIME will reset the system time.

mBTypically, you will want to establish the MBM time value once, andGprobably setting it to UTC or such, and you will then want to boot eachd/partition conversationally, setting the SETTIMErCsystem parameter to force the entry of the time within each booting6Gsystem environment. Once the MBM time value has been set once, you willSGtypically not want to alter it again. You will typically want to manageS6and modify only the time values within each partition.

DThe time and data values stored in the primary MBM and replicated inGthe zero or more secondary MBMs that might be present within the systemhare coordinated.

,?To enter the PMU from the SRM console, and to exit back to SRM: 

s 
s
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(MBM - (PMU, Platform Management Utility)(  From SRM P00> enter {Esc} {Esc} MBM5  CTRL/[ CTRL/[ MBM           (MBM must be uppercase)r1  MBM> connect                (to exit to SRM)

3


=BThe [CTRL/][ is the escape character. Use the cited keyAsequences to enter the PMU. You can also access the PMU through a Amodem, or from a terminal or terminal emulator or terminal server Dconnected to the server management LAN. Having the server managementFLAN bridged to an untrusted LAN can be unwise, however, and with risksDanalogous to those of configuring a traditional VAX or Alpha console=serial line to an open terminal server or to a dial-in modem.t

eDSee the AlphaServer GS1280 documentation for additional information.w

4.7 UTC vs GMT vs vs UT1/UT1/UT2 TDF? What are these acronyms?

u

PEThe results of an international compromise---though some would say anuBinternational attempt to increase confusion---UTC is refered to asE"Coordinated Universal Time" (though not as CUT) in EnglishtGand as "Temps Universel Coordinné" (though not as TUC)>Cin French. (No particular information exists to explain why UTC waso@chosen over the equally nonsensical TCU, according to Ulysses T.<Clockmeister, one of the diplomats that helped establish theinternational compromise.)

UCUniversal Time UT0 is solar time, UT1 is solar time corrected for apBwobble in the Earth's orbit, and UT2 is UT1 corrected for seasonalArotational variations in rotation due to the Earth's solar orbit.o

iGGMT---Greenwich Mean Time---is UT1. GMT is the time at the classic site?of the since-disbanded Royal Greenwich Observatory; at the mostt6widely-known tourist attraction of Greenwich, England.

aEUTC is based on an average across multiple atomic clocks, and is kept @within 0.9 seconds of GMT, through the insertion (or removal) of@seconds. In other words, UTC matches GMT plus or minus up to 0.9seconds, but UTC is not GMT.

>ETDF is the Timezone Differential Factor, the interval of time betweeniGthe local time and UTC. Areas that celebrate daylight saving time (DST) @will see periodic changes to the TDF value, when the switch-overFbetween daylight time and standard time occurs. The switch-over itselfGis entirely left to local governmental folks, and can and has varied byIFpolitical entity and politics, and the switch-over has varied over the years even at the same location.

EIf your local OpenVMS system time is off by one hour (or whatever theNDlocal DST change) for some or all applications, you probably need to?reset your local TDF. (For related details, please see sectionsSection 4.4 and Section 10.22.1.)t

mAFurther discussions of history and politics, the Royal Observers'sDoutbuildings, and the compromise that left the English with the TimeCStandard (the Prime Meridian) and the French with the standards for2GDistance and Weight (the Metric System) are left to other sources. Somer2of these other sources include the following URLs:

n

s


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m#w6h ctory:

 

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SYS$COMMON:[SYSEXE]




If the DCL command:

 
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