Scenario: Adjusting the system time 3 minutes

 

You can manually adjust the system time by 3 minutes. A time adjustment is different from changing the time of day system value. A time adjustment is the suggested method for system time changes.

 

Situation

As an administrator of your company's network, you need to maintain the system time on your System i™ platform. Your system is set to use the Eastern Standard Time zone, but you notice that the system time on your system is off by 3 minutes. Instead of manually setting the system time using the time of day system value, you need to make a time adjustment to ensure that your jobs run with the proper time. This also ensures that time does not jump either forward or backward in one instantaneous change.

 

Objectives

In this scenario, MyCompany, Inc. needs to adjust the system time 3 minutes. Jobs retrieve their time values from the system time. Therefore, it is critical that the system time be accurate so that jobs run with the proper time.

The objectives of this scenario are as follows:

• To adjust system time backward 3 minutes

• To ensure that jobs run with the proper time

• To ensure that time does not jump forward or backward in one instantaneous change

 

Details

The system time on System A is 3 minutes ahead. The system time needs to be slowed down until it is set to 3 minutes less than the current time. You cannot manually change the time of day system value because this can essentially repeat the last 3 minutes of system time. This type of repetition can cause unpredictable errors, if time-sensitive programs are running.

 

Prerequisites and assumptions

Based on this scenario, your system must meet the following requirements to make a time adjustment:

• Your system is using V4R5 or later hardware.

• You are running i5/OS^® V5R3, or later.

• You are using IBM^® iSeries™ Access for Windows^® V5R3, or later, to communicate with your system.

• Your system does not retrieve UTC from an external time source.

In addition, you should turn off any time maintenance applications in use. A manual time adjustment might conflict with any adjustments that the time maintenance application might make.

 

Time-adjustment steps

Assuming that time adjustments are allowed on your system...

1. From iSeries Navigator, expand My Connections > System A > Configuration and Service > Time Management > Time Adjustment.

2. On the Time Adjustment dialog box, click Start a new time adjustment. If a time adjustment is in progress, the current time adjustment will be stopped. Before proceeding, make sure that the current adjustment can be stopped.

3. Specify -0:03:00 (3 minutes).

4. Click OK to start the time adjustment.

5. View the Time Adjustment fields on the Time Adjustment dialog box. The following fields should be displayed:

   • Adjustment in progress: Yes

   • Adjustment remaining: HH:MM:SS (where HH represents the hours, MM represents the minutes, and SS represents the seconds)

   • Estimated time until completion: HH:MM:SS

A time adjustment is in progress until the system time reaches the time value specified. Click Refresh Now to update the statistics displayed.

 

Parent topic:

Scenarios: Working with time zones and time adjustments

Related concepts
Time adjustment