LOL …kids.:rolleyes:
Good thing this thread is not about my '79 Cutlass.
Actually, having a whole PC controlling this system is overkill. There is no need to upgrade either the computer or the software, just a minor tweak. In fact, had the DST not changed, the system would run perfectly with almost no maintenance at all.
I’m guessing the DST control “switch” is embedded somewhere in the automation software the PC is running. And unless you have the source code for that (if it was a custom job for the building) or the authors were forward-thinking enough to make DST change date user-modifiable (and good luck finding the documentation) via a menu or configuration file, you’ll probably have to live with making the change manually.
I’m guessing if you go with the FreeDOS with TZ support route, you’ll get the automatic DST change on the modern dates, but the existing software will blindly push the computer forward ahead/back another hour when the old dates hit, thus you’ll still have to fix the clock manually, which means you’ve gained nothing but adding an element of unknown into the system (perhaps the automation relies on the existence of some glitch in old MS/PC-DOS that FreeDOS “fixed”).
This is what I am suspecting now.
Another avenue would be to set it to another time zone that doesn’t observe DST, but where?
There should be an Arizona timezone that would be mountain time with no DST. or just set it to UTC.
Edit your autoexec.bat file add the following line
SET TZ=MST+07
If you exclude the DST setting which would be on the end, it will not adjust for daylight savings time. that is for Mountain Standard time, adjust the abbreviation and UTC offset for your timezone.
The dates that would change for the daylight savings time are compiled into command.com and not changeable.
Yes, this is the change I mentioned in the OP. I am going to try setting it for UTC and see what happens in October.
You may be able to look at the autoexec.bat file to find what programs are being loaded to the machine at startup. If there is one that looks like your time-changing culprit, you may be able to remove it from the autoexec and replace it with some other program like the ones mentioned above.
You acted like in your OP that you think you actually have to wait for the date. Just making sure you realize you can set the date up to test it. Windows will allow you to change it in the Date/Time control panel (in the Main program group in Program Manager).
But I’m pretty sure the change is either being made by a separate program or the automation software, so this likely won’t fix anything.
I did have another idea: the scheduling software may have the daylight savings change as an actual scheduled item. Even if it doesn’t, you may be able to schedule a clock change manually. Then just move on to using FreeDOS as mentioned. which has timezone support.
And I’m already working on that hack I mentioned earlier, just in case it’s the only possible solution. I accidentally took a wrong turn and am having to fix some stuff.
So I need you to answer the question implied by my parentheses earlier: How often is this computer rebooted?
The computer is almost never rebooted.
The problem is that if I force a time change by changing the date, it will take at least 2 days to re-synchonize all the clocks on the system, which is out of the question right now.