SY-DAYST System Field

Ok guys, I really need some help here. The system field SY-DAYST is used to determine whether it is Day Light Savings Time or not. If so, it is set to "X", if not, then blank. The problem is, is that we are currently on Daylight Savings Time, and this flag is not set in my system. I have been looking around and it appears that this flag is set at the operating system level. But we do not know how to set this flag. We are running on an AS400. Does anyone have any expericence with this?

Regards,

Rich Heilman