16 Sep Don’t Lose an Hour with your NetWeaver ABAP or Fiori Hub Systems
SAP has provided very useful tools to assist with post-processing steps after performing an SAP installation. Originally, SAP Note outlined the steps. This process was further enhanced with the introduction of the ability to dispatch all the typical housekeeping jobs directly from transaction SM36. Later improvements came with transaction STC01 and appropriate task lists. Despite having all of these tools available, it’s very easy to overlook a critical system setting, Daylight Saving Time (DST)
The history of Daylight Saving Time (DST)is an interesting one. DST has been around for many years. During World War I, many nations adopted DST as a mechanism to save energy. The practice of rolling clocks forward in one season and rolling them back in another has caused many challenges. This is especially true for events and processes that rely on precise timekeeping. Early software and computers addressed the change by a system restart during the time the clocks rolled ahead. Then shut down for a period equal to the amount of time the clocks needed to roll back. Eventually, software got sophisticated enough to accommodate the change and system stoppages were no longer required.
SAP software uses configuration tables that contain the DST rules. When you do a new installation of the NetWeaver ABAP stack, a default set of DST rules is deployed. We can view these settings using transaction STZBD and selecting ‘Variable Summertime rules’. The screen capture below is from a NetWeaver 7.52 system immediately after the installation process completed. In the screen capture, we see that effective beginning in the year 1990, USA DST is scheduled to begin on the first Sunday of April and will end the last Sunday of October.
In 2005, the United States Congress passed a law that beginning in 2007, DST would begin the second Sunday of March and would end the first Sunday in November. Due to this law, the default settings for DST in the SAP system do not reflect the reality of today. If you do not address this shortcoming, your SAP systems will be off by an hour for those portions of March and October.
To correct this, you have the option to either make an appropriate entry on your own or use my preferred approach, following the instructions in SAP Note 198411. This note has a .zip file that contains documentation of Time Zone information in the SAP system that you can access via a browser.
More importantly, the .zip file contains file tzdata.dat. Its contents are the current time zone rules. To apply the file, run report tzcustim and import the tzdata.dat file in your development system. This will prompt you for a transport request.
After executing report tzcustim, we see the rules for US DST are now accurate. The new rule is: Effective in 2007, USA DST will start on the second Sunday of March. Then it will end the first Sunday of November.
As a Basis Administrator, it is possible to perform all of the post-installation tasks as defined by the installation guides and the SAP supplied tools. Yet, this easily-overlooked correction has the potential to become very visible within your organization. By executing the above report to import the corrected DST settings, you will ensure that the system(s) will properly respond to the Daylight Savings Time adjustments.