sys$timezone_daylight_saving logical

[TMcB]

Hi folks

I was wondering if the logical sys$timezone_daylight_saving logical is still used.

British Summer Time comes into effect this weekend, and I was testing the dst$change.com program.

The logicals at present are :
"SYS$TIMEZONE_DAYLIGHT_SAVING" = "0"
"SYS$TIMEZONE_DIFFERENTIAL" = "0"
"SYS$TIMEZONE_NAME" = "GMT"
"SYS$TIMEZONE_RULE" = "GMT0BST-1,M3.4.0/01,M10.5.0/02"

The time goes forward 1 hour on Sunday, and after running dst$change, the time does go forward one hour correctly, but the logicals are as follows ;

"SYS$TIMEZONE_DAYLIGHT_SAVING" = "0"
"SYS$TIMEZONE_DIFFERENTIAL" = "3600"
"SYS$TIMEZONE_NAME" = "BST"
"SYS$TIMEZONE_RULE" = "GMT0BST-1,M3.4.0/01,M10.5.0/02"

The problem is that the sys$timezone_daylight_saving logical should have changed to 1.

I think this should be happening is sys$manager:utc$time_setup.com " " "TDF" 60 60

Is anyone aware of any problems with this?

Thanks

[Volker Halle]

Hi,

after switching to summer time, you should see:

SYS$TIMEZONE_DAYLIGHT_SAVING = 1

to indicate, that you are running in the daylight saviongs time period.

I tested this recently with AUTO_DLIGHT_SAV = 1 on V7.3-1 and it worked as expected (in MET time zone).

Volker.

[TMcB]

Thanks for getting back to me.

We do not use the auto_daylight_save logical.

I have tested this on 2 different servers running 7.3-2, and the logical remains at 0.

[Ian Miller.]

How are you changing to BST?

[Garry Fruth]

I believe Volker was refering to the AUTO_DLIGHT_SAV sysgen parameter, not a logical name.

Auto_dlight_sav worked well for us last fall using 7.3-2 and interacted well with HP TCP/IP NTP service. One kicker tough, a maintenance job ran at 2am that did a SYSMAN SET TIME/CLUSTER, the same time the clock was to fall back; the side effects were interesting. I suggest doing SET AUDIT/AUDIT/ENABLE=TIME; it helped us find the maintenance job (ANALYZE/AUDIT/EVENT=TIME).

You may want to read through http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=730417

[Volker Halle]

Results from testing:

SYS$EXAMPLES:DAYLIGHT_SAVINGS.COM

Version X-3 (OpenVMS Alpha V7.3-1 with VMS731_UPDATE-V0200, AUTO_DLIGHT_SAV=0, no DTSS):

- will correctly switch from MET to MET DST
- will DELETE logicals SYS$TIMEZOME_DAYLIGHT_SAVING and SYS$TIMEZONE_NAME (as can be seen in the DST$CHANGE.COM file created)


Version X-6 (from V7.3-2 on the same V7.3-1 system as above):

- will correctly switch from MET to MET DST
- will correctly update logicals, including SYS$TIMEZOME_DAYLIGHT_SAVING = 1


I would strongly suggest to use the AUTO_DLIGHT_SAV = 1 system parameter (available since OpenVMS Alpha V7.3) with the most recent TDF patches installed or use DTSS.

Volker.

[TMcB]

Hi

We are running mixed architecure VAX / ALPHA clusters and I thought I read somewhere that it is not advisable to use the auto sysgen parameter in this mode.