Others have mentioned XCF and system stuff, there are also application considerations.
It depends on your applications and how they are written. If they use the TIME macro, or the various language equivalents, you may have a problem at switch times. See the ZONE parameter of the TIME macro. During the transition in the Spring, you can have a few transactions that look like they ran an hour longer than they did. In the Fall you can have transactions that look like they end before they begin. If the programmers coded ZONE with the right option, then there is no problem. For those that are still sensitive, what you can do is stop processing those applications just before the switch time and restart the processes right after without doing the IPL. In the Spring that means you need about a 10 minute outage. In the fall you have to stop them for about an hour and ten minutes to let the clock catch back up. This is a programming short-coming and I have been of the opinion for 10 years that they need to fix it and stop making operations jump through hoops every Spring and Fall. Just my personal 2 cents on this. Chris Blaicher Senior Software Engineer, Software Services Syncsort Incorporated 50 Tice Boulevard, Woodcliff Lake, NJ 07677 P: 201-930-8260 | M: 512-627-3803 E: [email protected] www.syncsort.com Check out our Knowledge Base at www.syncsort.com/support Syncsort aims for the best product and service experience. We welcome your feedback. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Dazzo, Matt Sent: Monday, November 21, 2011 2:13 PM To: MVS List Server 1 Subject: Set Clock Command We are a monplex environment with the SE clock set to locale time, we run DB2, CICS and DASD XCF dataset. Our current procedure for time change is to shutdown MVS, change the SE clock and IPL. Clock=00 member has no off set and has been set up like this since the beginning of time. I have been looking at the set clock command in hopes of maybe eliminating the IPL. From reading the good old book I think I have to do the following. Anything else I am missing or should be aware of? How does the DASD XCF dataset handle the time change when going back 1 hr? Thanks Matt 1.Set the SE clock to GMT 2. Change the TIMEZONE to -5 for EST ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
