[7.3 VAX] NTP and daylight saving time

[JKB]

Hello,

My VAX runs OpenVMS 7.3 and I uave configured NTP client some
months ago.

Today, I have seen that clock was not synchronized. SHOW TIME
returns a difference greater than 4 hours between OVMS client and
NetBSD server.

I have restarted NTP.

$ type TCPIP$NTP_RUN.LOG
29 Oct 08:57:13 ntpd version = 4.1.0
29 Oct 08:57:14 precision = 10000 usec
29 Oct 08:57:16 drift file 'SYS$SPECIFIC:[TCPIP$NTP]TCPIP$NTP.DRIFT' does not e
xist: no such file or directory
29 Oct 08:57:17 will attempt to create drift file
29 Oct 09:01:41 time correction of 3607 seconds exceeds sanity limit (1000); se
$ show time
29-OCT-2024 14:15:21

On server side :
hilbert:[~] > date
mar. 29 oct. 2024 14:15:34 CET

I have checked timezone with @SYS$MANAGER:UTC$TIME_SETUP.COM and, for
me, configuration correspond to Europe/Paris time.

Server use UTC. For me, client use UTC also and only SHOW TIME does
time conversion from UTC to local time. I suppose I have done a
mistake somewhere, but where ?

Regards,

JB

[Arne Vajhøj]

Post by JKB
My VAX runs OpenVMS 7.3 and I uave configured NTP client some
months ago.
Today, I have seen that clock was not synchronized. SHOW TIME
returns a difference greater than 4 hours between OVMS client and
NetBSD server.
I have restarted NTP.
$ type TCPIP$NTP_RUN.LOG
29 Oct 08:57:13 ntpd version = 4.1.0
29 Oct 08:57:14 precision = 10000 usec
29 Oct 08:57:16 drift file 'SYS$SPECIFIC:[TCPIP$NTP]TCPIP$NTP.DRIFT' does not e
xist: no such file or directory
29 Oct 08:57:17 will attempt to create drift file
29 Oct 09:01:41 time correction of 3607 seconds exceeds sanity limit (1000); se
$ show time
29-OCT-2024 14:15:21
hilbert:[~] > date
mar. 29 oct. 2024 14:15:34 CET
me, configuration correspond to Europe/Paris time.
Server use UTC. For me, client use UTC also and only SHOW TIME does
time conversion from UTC to local time. I suppose I have done a
mistake somewhere, but where ?

"3607 seconds" is likely clock 7 seconds off and time zone 1 hour off.

Has it always been like this or did it happen when Europe switched
to winter time in the weekend?

I suspect that the TZ config may have CET/MET without DST
instead of CET/MET with DST with a wrong clock that gave the correct
result on summer time and and wrong result on winter time. But that
is pure speculation.

Arne

[Volker Halle]

Post by JKB
Hello,
My VAX runs OpenVMS 7.3 and I uave configured NTP client some
months ago.
Today, I have seen that clock was not synchronized. SHOW TIME
returns a difference greater than 4 hours between OVMS client and
NetBSD server.
I have restarted NTP.
$ type TCPIP$NTP_RUN.LOG
29 Oct 08:57:13 ntpd version = 4.1.0
29 Oct 08:57:14 precision = 10000 usec
29 Oct 08:57:16 drift file 'SYS$SPECIFIC:[TCPIP$NTP]TCPIP$NTP.DRIFT' does not e
xist: no such file or directory
29 Oct 08:57:17 will attempt to create drift file
29 Oct 09:01:41 time correction of 3607 seconds exceeds sanity limit (1000); se
$ show time
29-OCT-2024 14:15:21
hilbert:[~] > date
mar. 29 oct. 2024 14:15:34 CET
me, configuration correspond to Europe/Paris time.
Server use UTC. For me, client use UTC also and only SHOW TIME does
time conversion from UTC to local time. I suppose I have done a
mistake somewhere, but where ?
Regards,
JB

JB,

SHOW TIME does not do any time conversion.

On VAX you might need to run sys$examples:daylight_savings.com to switch
between daylight savings time and normal time.

$ sho log sys$time*
...

(LNM$SYSTEM_TABLE)

"SYS$TIMEZONE_DAYLIGHT_SAVING" = "0"
"SYS$TIMEZONE_DIFFERENTIAL" = "3600"
"SYS$TIMEZONE_NAME" = "MET"
"SYS$TIMEZONE_RULE" = "MET-1MET_DST-2,M3.5.0/2,M10.5.0/3"

Regards,

Volker.

[Lawrence D'Oliveiro]

Post by Volker Halle
SHOW TIME does not do any time conversion.

On VMS, the system clock is in local time, not UTC, isn’t it?

That design feature is inherently prone to time-transition screwups.