Purpose
The purpose of this wiki document is to make the timezone related issues are addressed with respect to an SAP system. This document explains the different levels of timezone that is set in the SAP system.
Overview
At times its needed to adjust the SAP servers timezone when there is a daylight savings DST switch. During this time switch there needs to proper procedure followed to correct the time zones. SAP system and OS (Operating system) should be the same to avoid time differences and errors. In case if they are different then you may use the below reports to set them appropriately.
System Logic
The timezone is set at different levels of an SAP system.
1. Operating System Time [CPU Clock Settings]
2. Time zone at Client [Transaction Code STZAC]
3. User time zone [Transaction Code SU01/SU3]
Changing the system time zone on SAP system should not have any influence on existing data, because the times/dates on database are stored with a certain time stamp and these are not influenced by the time zone changes. The sequence and the chronological order of the document will remain the same. In the transaction STZAC you do have the following two time zone input fields:
System Time Zone <If an application is started in a client it can use this client time zone setting>
User's Default Time Zone <If a user is connected to a client and for this userid if there is no time zone setting defined in the transaction SU01 of this client then the user time zone will be
automatically set to the time zone value which is defined in this field here>
How to check the timezone at different levels
- Login to SAP system client
- Run the report from Tcode SA38 -> TZCUSTHELP
- Run the report from Tcode SA38 -> RSDBTIME
- Run this function module in SE37 -> TZ_SYSTEM_GET_TZONE
- Run this report from Tocde SA38 -> TZONECHECK
How to check on OS level Windows Servers
- Windows - Run – cmd – Systeminfo
C:\Users\ABCD>systeminfo - The output has the below information.
Host Name : 111233798A
OS Name : Microsoft Windows 10 Enterprise
OS Version : 10.0.10586 N/A Build 10586
Time Zone : (UTC+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna
Unix Systems : datedate : Thu Apr 27 09:19:56 CEST 2017
Recommendation
- If you would like to update your system with the newest time zone data, then I would recommend to check note 198411 regularly.
- If you change timezone in STZAC it affects only the SAP instance timezone and only SAP system needs to be restarted.
- If you change the database time then you need to restart both SAP instance and Database Instance.
- Don't change the settings in STZAC when the users are connected to the system
- The 'System Time Zone' will be automatically changed for all clients but for the 'User's Default Time Zone' setting you have to start the transaction STZAC in each specific client.
- We always recommend a downtime during the switch from daylight saving time to winter time to avoid issues during the so called "double hour".In this period the time does not run constantly and we cannot guarantee that the software can handle the situation if a point of time comes up twice.
Refer SAP note 102088 - Reducing downtime when changing from summer to winter time - One possibility to avoid the downtime is the system time setting UTC. Then no daylight saving time switch is performed at all and so no downtime is needed.
Points to Consider when Setting timezone on UTC
Once your systems are set to UTC timezone then end users can continue to work in the coming years.
Yes the end users can continue to work. With UTC set as the system time zone users can just continue to work. No double-hour – no reason to stop working.
When the system timezone is set to UTC, then all the os processes running for the SAP application server AND the DB listener process must run in local time zone UTC. Otherwise you gonna get lots of dumps.
When you switch to system time zone UTC and your former system time zone has been a timezone east of Greenwich ( central Europe, Asia, … ) then you have to shutdown the system at least for the difference of the former system timezone and UTC. Example: central India is 5 ½ hours east of Greenwich, so the system must be shutdown for 5 ½ hours. The reason for this is that a system timestamp must not occur twice in a system
Additional information in the below WIKI
https://wiki.scn.sap.com/wiki/display/Basis/Time+zone+settings%2C+SAP+vs.+OS+level
Recommended SAP notes
7417 Conversion between standard time and daylight saving time
1603349 Downtime during DST time change
2216792 How to set UTC as time zone
2006897 How to compare timezone settings between OS and application server with report TZCUSTHELP
1525336 How to change timezones in the SAP system
612883 System time zone after cross-system client copy
For Java instance specific information
1118594 How to handle time and date when using Java WS Consumers
Related Content
TZCUSTDISP Display System Parameters for Time Zones
TZCUSTHELP Troubleshooting Support for Time Zone Settings
TZONECHECK Check Time Zone Data for Consistency
TZCUSTIM Import Customizing Data
TZCUSTEX Export Time Zone Data
RSDBTIME Time diagnosis
Related Documents
Related SAP Notes
481835 Analyzing the time zone settings
198411 Current data and information about time zones
7417 Conversion between standard time and daylight saving
741734 Incorrect times due to the time zone settings
926290 SWNCCOLL: SAP workload NW collector collects no data
1375438 Globalization Collection Note > point 3
7 Comments
Lamarti Zobair
Dear Naveen,
Very good guide. Thank you.
I have a question:
What is the added value to maintain "Fixed Summer time rules"?
For example, please check note "2232043 - No daylight saving time in Uruguay from year 2015 onwards".
Is there an added value to maintain the table "TTZDF"?
When this table is used?
Thank you for your reply,
Zobair
Nils Buerckel
Dear Zobair,
the added value is to have an updated set of worldwide time zones. Hence if somebody is using Uruguay time as local time (Time zone of the user in transaction SU3 ) he gets the correct time displayed.
You can implement this one with the help of attachment of 198411.
Best regards,
Nils
Adriano Augusto Prehs
Dear Naveen,
Is there any way to enter/exit in Daylight TimeZone automatically without downtime (Stopping for 1 hour)?
Kind Regards
Adriano Prehs
Naveen Kumar Vasan
Dear Adriano,
This is not possible due to application restrictions. Please follow regular method as described in notes for Timezone changes.
Regards,
Naveen.
Former Member
You can avoid the downtime if your system runs UTC, refer to note 7417:
If the system time is UTC (Coordinated Universal Time), this problem does not occur and there is no reason for you to shut down the system when there is a switch from daylight saving time to standard time.
Former Member
Also without UTC system time
Derek Yang
Dear Naveen,
This is Derek from SAP Global Trade Service development team. Could you please mention for specific SAP application, it is NOT allowed to change the system time zone after system setup?
For example, in SAP GTS(Global Trade Service), tables are designed to reflect the timezone changes, date are converted to timestamp using UTC timezone and saved into database. If system time zone is changed, it will lead to major data inconsistencies.
Regards,
Derek