Adam wrote:

> --- In firebird-support@yahoogroups.com, Lester Caine <lester@...> wrote:
>> Adam wrote:
>>
>>> The clocks on all OSes supported by Firebird use UTC *natively*, and
>>> only convert to a local representation upon request. In Windows for
>>> example, GetLocalTime is internally a wrapper around GetSystemTime and
>>> SystemTimeToTzSpecificLocalTime.
>> Please can you provide some more proof on this.
>
> http://msdn.microsoft.com/en-us/library/ms724493(VS.85).aspx
>
> In terms of hardware clock weirdness, I can not explain, but it is
> getting pretty OT.

Bottom line. It is a fact that in the past we have had major problems with
maintaining consistent time information in the databases when windows is
involved. The REALITY of both W2k and XP does not match the link you provide,
and while the GetSystemTime and GetLocalTime functions are available, on
Windows, the system time CAN be wrong if the hardware clock is not set
properly, and setting the clock manually EVEN FROM WINDOWS can give the wrong
base time!

In fact I've just checked GetSystemTime and GetLocalTime functions on an XP
machine, and it is quite possible for GetLocalTime to return 'UTC' while
GetSystemTime returns an incorrect offset time. Switching on internet update
of time seems to correct the fault, until you turn the power off, and then the
wrong time is saved to the hardware clock after a reset.

This *IS* on topic since it has been quoted may times before when people have
had problems with consistent UTC times being stored in the database using
'NOW'. Windows is simply inconsistent and needs care to ensure that the right
time is maintained, and the only reliable way of doing it *IS* to maintain the
hardware clock on UTC - so that Linux time's are also right - and then manage
windows WITHOUT using the faulty tools provided by M$. And during the hour of
a daylight saving overlap ( 2AM becomes 1AM ) windows applications get messed
up when a file timestamp is prior to a later save. Builder actually screws up
compiles at this point unless you have daylight saving switched off on the
development machine!

I don't know if this has been fixed in Vista but that introduces another level
of complexity that is pointless for a server machine.

--
Lester Caine - G8HFL
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