[fpc-devel] NowUTC in the RTL

[waldo kitty]

On 12/13/2011 04:17, Tomas Hajny wrote:
> On Tue, December 13, 2011 01:08, waldo kitty wrote:
>> On 12/9/2011 07:13, Tomas Hajny wrote:
>>>
>>> Obviously assuming that something like that is possible on a certain
>>> platform at all (GO32v2 not having the TZ environment variable defined
>>> will simply never be able to provide UTC time; in fact, the same applies
>>> for OS/2 / eCS too).
>>
>> never say never... my OS/2 systems do know about and use the TZ
>> environment variable... some programs on those systems also use the TZUTC
>> environment variable... my oldest OS/2 system is Warp 3 Connect and it has
>> been using these EVs since Warp 3 Connect was made available to the public
>> ;)
>>
>> now, i should point out, which i kinda of lightly did above, that the OS
>> may or may not use these but those programs which know about them can and
>> do...
>
> I don't say never, just that neither DOS nor OS/2 enforce or validate this
> setting and thus it's purely up to the user to make sure that it
> eventually works.

i understand and yes, you are right, neither of them enforces or validates this 
setting... i was, actually, aiming at "never" in "[...] will never be able to 
[...]" all my systems, OS/2, DOS, Winwhatever, and linux are set to local 
time... when they need to provide a UTC timestamp, they do otherwise it is local 
time... at least this is my experience and has been for "ever"... i have never 
run any of my systems in UTC time and expected them to convert all the time to 
local time...

however, back to the TZ and such... i wrote a library for TP6/BP6 that emulated 
parts of the C time stuff using a slightly modified tm_rec... i needed this so i 
could work on an external means of changing some settings when daylight saving 
switched on and off in my area... these settings were specific to a few programs 
and i wanted to automate the switchover so that their outputs were not an hour 
off either way... i even took the opportunity to "borrow" novell's DSTSTART and 
DSTSTOP style settings... they look like this...

DSTSTART=second sunday in march at 2:00
DSTSTOP=first sunday in november at 2:00

granted, that info may be gleaned from the long form of TZ but i didn't code for 
that in my stuff at that time... i was only interested in the current timezone, 
what the offset from UTC was at the time, and when daylight saving switched on 
and off... i still use this at least eight year old code in numerous projects i 
still maintain with TP/BP6 ;)

> Not even mentioning the attempts of an author of certain
> command shell who apparently tries to make the situation even more
> confusing (however smart he may be) by trying to convince others that IBM
> wanted something else than what they really did :/ (if you don't know whom
> or what I talk about, forget it, it isn't very important).

yes, i know exactly who you are talking about ;)  i was an active beta tester of 
his products as well as a distributor of them on fidonet... i'm still on fidonet 
but haven't heard anything from JdBP in a long while...