Monday, June 23, 2008

Crossing through winter daylight <-> saving time within SAP?

Some people saying that switching from Daylight saving time (DST or just simply summer time) to winter time and vice versa; is not good for humans because it most likely causing heath problem but even software has a trouble with it. SAP in not exception.

During this period; that time is “being changed” clock is shifter back and one precise hour of time may happened “twice”. Problems with your SAP installation that may occurs can be like following:

  • Start of periodically scheduled background jobs might mismatch and data being processes by then might be inconsistent.
  • BI loads may fail
  • Backuping/archiving might be unstable.
  • Wrong time synchronization of buffers, timestamps, timeouts, and time refreshes error.

What to do? It depends on your system. Basically golden rule would be to shutdown SAP system for at least one hour (ideally for two hours) at during this critical period of time switch. Problem is in case if you cannot effort that system outage. In this case make sure that you never put system clock on machine where SAP is running to past.

For further information please consult following SAP notes:

7417 - Conversion between winter time and daylight saving time

438660 - End of daylight-saving time coming soon, be ready!

102088 - Reducing downtime when changing from summer to winter time

398374 - Problems when converting summer time <-> winter time – SAPTTZ tool to determine technical properties of the current time zone.

1 comment:

Vinay Sah said...

Hi,
As a new challenge, i have a task to maintain an SAP sysyem as an abap programmer. Requirement is to maintain the system according to the coming day light saving changes. Can you please tell me what things i have to change in the system to adapt the system for day light savings. A step by step procedure will be appreciated.

Regards,
Vinay Sah