[Info-vax] Does anyone know if the unsupported TBO (time boost utility that "drifts" time forward or backward by adjusting ticklength) was every ported to the Itanium?

[Chris]

On 10/30/20 01:56, Stephen Hoffman wrote:
> On 2020-10-30 01:27:43 +0000, Chris said:
>
>> How does VMS keep time ?.
>
> OpenVMS and most apps use a quadword value containing centiseconds
> typically configured for localtime, and with few apps having adopted the
> UTC timekeeping that semi-recent OpenVMS versions can also provide.
>
> Here's some general reading on this topic from the old FAQ and from the
> current manuals:
> http://www.hoffmanlabs.com/vmsfaq/vmsfaq_004.html#faq_time
> https://vmssoftware.com/pdfs/HP_branded_docs_1st_batch/HP_OpenVMS_System_Managers_Manual_Vol1.pdf#page=173
>
>
> If after having read through that and should you still have questions,
> stop back and I'll try to either clarify or confuse things more.
>
> C provides the C APIs, as do other languages.
>
> Details here do vary over the versions, with OpenVMS V7.3 and later
> having integrated support for timekeeping and timezones—older releases
> had that data largely in either the IP or DECnet-Plus stack.
>
> V7.3 was when there started to be timezone-related prompts at OpenVMS
> install time, among other updates.
>
>> Does it use ntp, or some system of it's own ?.
>
> OpenVMS uses its own local timebase, unless specifically configured for
> NTP or DECnet-Plus DECdtss.
>
> When OpenVMS and the IP or DECnet-Plus network stack is configured to
> synchronize using NTP or DECdtss, those mechanisms then use system APIs
> to manage and to drift the system time.
>
> NTP presents the system with UTC values, meaning arithmetic to convert
> UTC to localtime.
>
>> Most of the world seems to use UTC +/- offset these days, which seems
>> sensible...
>
> Localtime. And twice a year the localtime value shifts either manually
> or automatically, for those that still "celebrate" DST.
>
> Which is at the core of this thread.
>
> DEC OpenVMS by way of DEC MICA is where Microsoft Windows inherited its
> bad timekeeping ideas from, too.
>
> Put differently, if you could pick a simple and utterly wrong approach
> to timekeeping, that'd be what OpenVMS uses. Heap on ~forty years of app
> upward compatibility, and things get even more muddled.
>
>
>
>
Thanks for that, not something I had thought much about. I guess there
will be a move to UTC as baseline at some stage, with all else
calculated from that...

Chris