Use this command to:
- Change the system time-of-day (TOD) clock
- Change the subsystem local standard time (LST) clock
- Synchronize the TOD clock to a Sysplex Timer.
Requirements and Restrictions
- Enter the ZDTIM command to determine the time base before you enter this
command.
- If you enter this command when the TPF system is above 1052 state, you
must cycle the TPF system to 1052 state to complete the time
adjustments.
- You can enter this command with the TOD parameter only in 1052
state.
- In a loosely coupled system, all other active processors must be in 1052
state in order to change the TOD clock without the BP option.
- The ZATIM command does not adjust time-initiated functions (that is,
functions that were started by using the CRETC macro).
Format
- timebase
- is the time base specified in hours (hh) and minutes
(mm).
- Note:
- Enter the ZDTIM command to determine the time base.
- SET
- changes the subsystem LST clock.
- Note:
- You can specify this parameter only when cycling is enabled. Enter the
ZPSMS command to enable cycling.
- ADD
- adds the specified hours and minutes to the LST clock.
- hhmmss
- is the hours, minutes, and seconds.
- mmddyy
- is the month (mm), day (dd), and year
(yy).
- Note:
- Years ending in 00 through 41 are considered to be in the 21st
century. Therefore, you can specify dates from January 1, 1942 through
December 31, 2041.
All the processors in a loosely-coupled complex have the same format of
days, months, and years.
- ddmmmyy
- is the alternate date format with day (dd), month (mmm),
and year (yy). Specify the month as one of the
following:
- JAN
- specifies January
- FEB
- specifies February
- MAR
- specifies March
- APR
- specifies April
- MAY
- specifies May
- JUN
- specifies June
- JUL
- specifies July
- AUG
- specifies August
- SEP
- specifies September
- OCT
- specifies October
- NOV
- specifies November
- DEC
- specifies December.
- TOD
- changes the time-of-day clock for the specified date.
The TOD parameter is valid only for the basic subsystem (BSS). It
changes all the subsystem clocks when the subsystem is cycled above 1052
state.
- Note:
- Enter the ZDTIM TOD or ZDTIM STR command to determine the time base for this
command.
- GOOD
- indicates that the current value of the TOD clock is acceptable and the
value will not be changed.
If you specify this parameter with the STR parameter, the TOD clock is
synchronized to the Sysplex Timer. This command is transparent to all
other central processor complexes (CPCs) in the complex.
- STR
- specifies that the time source is the Sysplex Timer.
- ALTPORT
- specifies that the time source is the Sysplex Timer on the alternate
port.
This parameter is valid only when each port of a CPC goes to a different
Sysplex Timer and these Sysplex Timers are uncoupled.
- Note:
- You cannot specify this parameter when running under Processor
Resource/Systems Manager (shared PR/SM).
- STRNM-name
- indicates that TOD synchronization compatibility (TSC) hardware is being
used on the CPC and the Sysplex Timer should be used as the synchronization
source, where strname is the 1- to 4-character name of the Sysplex
Timer.
- Note:
- TSC hardware is required when there are TOD RPQ CPCs and Sysplex Timer CPCs
in the same loosely coupled complex.
- BP
- makes the TOD clock for the current processor the master TOD clock in a
loosely coupled complex.
- Note:
- You can specify this parameter only in a loosely coupled complex.
Additional Information
- Enter ZDTIM (with no parameters) to display the value of a
subsystem LST clock. Use this value as the base time if you change the
subsystem LST clock.
- When you change a subsystem LST clock, the TPF system immediately changes
the time difference between the system clock and the subsystem clocks, the
subsystem Greenwich clocks, and the subsystem perpetual clocks. In
addition, if the subsystem is above 1052 state, the global clocks and the
global calendar fields (if appropriate) are also changed. If the
subsystem is not above 1052 state, the global clocks and the global calendar
are updated when the subsystem is cycled above 1052 state.
- When a subsystem is in 1052 state, the SET parameter uses the last
midnight value of the subsystem perpetual clock to set the subsystem clock and
to determine the time difference between the system clock and the subsystem
clock.
- When a subsystem is in 1052 state, the ADD parameter calculates what the
time would be if the subsystem was above 1052 state, and adds the time you
specify to set the subsystem clock and the new time difference between the
system clock and the subsystem clock.
- After the TOD clock is set in the current processor, the other active
processors are notified that the TOD clock was changed. All loosely
coupled processors in 1052 state are automatically resynchronized. You
must perform an initial program load (IPL) on the other processors above 1052
state in order for them to update and synchronize their TOD clocks to the new
time. If an attempt is made to cycle one of the other processors above
1052 state without having synchronized its TOD clock, the cycle is
canceled.
- In a loosely coupled system, if the TPF system is waiting for TOD clock
confirmation and there are other active processors above 1052 state, you must
specify the BP parameter when you enter the ZATIM TOD command.
- When you enter the ZATIM command, loosely coupled processors above 1052
state are notified that they are no longer synchronized with the
complex. You must perform an IPL to resynchronize the clocks, or you
must cycle to 1052 state and enter the ZATIM command again. The
processors in 1052 state are resynchronized automatically.
- If you enter ZATIM TOD GOOD BP from the master processor, all
other processor clocks are not marked unconfirmed. These
processors are not notified that the TOD value was changed.
- Enter ZATIM STR GOOD to synchronize a single CPC with a Sysplex
Timer. You do not need to perform an IPL for the CPC. The CPC
connected to the Sysplex Timer has its ports verified; if the Sysplex
Timer ports connected to the CPC are operational and synchronized with the
master synchronization source, the CPC is synchronized to the remote Sysplex
Timer. This command is transparent to all other CPCs in the
complex.
- When you change the system TOD clock, the TPF system immediately updates
the system clock, the system Greenwich clock, and the system perpetual
clocks. The time differences between the system clock and each of the
subsystem clocks are not affected, and the subsystem clocks (and date, if
appropriate) are changed when the subsystem is cycled above 1052 state.
- The IBM 9037 Sysplex Timer is part of the IBM Enterprise Systems
Connection Architecture.
Examples
The basic subsystem (BSS) LST clock is changed to 11 a.m. in
the following example. The time difference between the system clock and
the BSS clock is updated as well.
+--------------------------------------------------------------------------------+
|User: ZDTIM |
| |
|System: DTIM0003I 11.26.32 SUBSYSTEM BSS CLOCKS ARE NOT RUNNING |
| |
|User: ZATIM 1126 SET 1100 |
| |
|System: ATIM0001I 11.00.32 SUBSYSTEM BSS LOCAL STANDARD TIME |
+--------------------------------------------------------------------------------+
In the following example, the TOD clock is set to the time and date that is
given by the Sysplex Timer. (You can enter the ZDTIM STR command to
determine the time and date of the Sysplex Timer.)
+--------------------------------------------------------------------------------+
|User: ZDTIM TOD |
| |
|System: CLKS0010I 11.00.32 TIME OF DAY CLOCK LOCAL STANDARD TIME |
| TIME: 14.56.54 DATE: 05/24/94 |
| CLKS0081I 11.00.32 SOURCE: MASTER STATUS: CONFIRMED |
| MASTER- CPUID: B SERIAL: 020410 MODEL: 3090 |
| |
|User: ZATIM 1456 TOD STR |
| |
|System: CLKS0010I 11.00.32 TIME OF DAY CLOCK LOCAL STANDARD TIME |
| TIME: 14.57.10 DATE: 05/24/94 |
| ATIM0002I 11.00.32 TIME OF DAY CLOCK SET |
+--------------------------------------------------------------------------------+
Related Information
See TPF Main Supervisor Reference and TPF System Generation for more information about the
system clocks.