The Curious Case of Resmed 10 Series Clock Setting

[S. Manz]

In my previous post regarding Resmed 10 inability to automatically adjust its clock for Daylight Saving Time , we had a great discussion and many invaluable insights into why it is that Resmed 10 series clock cannot be adjusted backwards (see screenshot of the message you'd get) without having to erase all the data first.
In that tread we finally came to accept the suggestion made by some posters that indeed "you can set the clock back, except that you must wait at least one hour, for every hour that you want to turn the clock backward" presumably after your last use of the machine. 
This made some sense because since the machine still has data from your last use in its memory, if you try to set the clock back to a time that was already covered by the machine when it was on and recording your CPAP data, then it would not know what to do what that part of the data !    ....Well, this thread is about the fact that that explanation isn't quite true

Let me first acknowledge the posters who explained that "Resmed clock goes from 12 noon to 12 noon next day"... Thank you because this seems to be the case.
I woke up at 5:30 AM sharp this morning and turned my machine off.
at 18:00 tonight ,I decided to run an experiment by setting the clock on my machine back by an hour---->no problem. Works fine
2 hours back----->No problem
3 hours back----->No Problem
4 hours back----->No problem
5 hours back----->No problem
6 Hours back----->No Problem
6 hours and 1 minute back-----> Message says "Date and time cannot be set in the past" 
I can set it more than 6 hrs back only if I erase the data first (remember more than 6 hours back from 18:00 hours, takes us to before noon (12))

So there must be something about 12 O'clock that makes Resmed 10 corky when it comes to setting its clock because it looks like it doesn't like its clock to ever be set backwards past noon.
Any ideas what on earth I am missing here? Why is this thing so peculiar about its clock?


   

[Jeff8356]

If I'm not mistaken, if you check your SD card shortly after noon you should see that there are some new files created even though your machine has been idle.
I just checked mine and it already has a folder set up for tomorrows (or tonight's as it were) data even though I haven't used it since this morning. Which is probably why you can't go past a certain point once the it passes noon.

Following that same logic....If you wait until 2300 (11pm) can you then go back 11 hours?

[cathyf]

If I'm not mistaken, if you check your SD card shortly after noon you should see that there are some new files created even though your machine has been idle.
I just checked mine and it already has a folder set up for tomorrows (or tonight's as it were) data even though I haven't used it since this morning.  Which is probably why you can't go past a certain point once the it passes noon.

Following that same logic....If you wait until 2300 (11pm) can you then go back 11 hours?

Yes. Actually you have all the way to 23:59 to start going backwards, and you can always go back to noon (1200 hrs) on that day. So if you are willing to stay up and move in multiple segments, you can move the clock back an entire 24 hrs.

At noon on the date MM/DD/YYYY, the machine creates the subdirectory in the DATALOG directory that has the name YYYYMMDD.

Any time that you turn the machine on during the time period that the machine's clock is saying that the date/time is after noon on MM/DD/YYYY and before noon on the day after MM/DD/YYYY, then the machine writes all of those data files into the MM/DD/YYYY folder. Those files have date/timestamps as part of their names.

Once you have passed noon, you can set the clock back to any time as long as that time is after noon on that day.

Once you cross midnight, the problem is that the interface makes it impossible to set the clock back even a few minutes if you need to cross back before midnight.

Example: On March 14th at 11:53pm I realized that the clock said that it was 12:06am on March 15th. So I set the time to 11:53pm and then went down to the next line to to set the date back to March 14th. But I had just told the machine that the day & time is 11:53 on March 15th! I fought with it for awhile and then went to sleep and recorded with the clock set one day into the future -- it was after midnight on March 16th according to the machine, and it put the data into the new 20210315 directory that it made instead of the 20210314 directory that it belonged.

I experimented, and realized that once I passed noon on March 15th -- and the machine's clock passed noon on March 16th, I could start setting the clock back, but only as far as noon on March 16th. So by midnight on the 16th I had managed to get the clock exactly 12 hours into the past, so it thought that it was noon on the 16th, now only 12 hours into the future. I went to sleep, and it wrote the files into the 20210316 directory, but with times all 12 hours in the future starting 1pm on the 16th rather than 1am on the 16th -- which should have gone into the 20210315 directory.

When I woke up at 8am on the 16th, the clock said 8pm on the 16th, and I set the clock back to noon on the 16th. By 1pm on the 16th, the clock said 5pm on the 16th, and it let me set the time (correctly) back to 1pm on the 16th.

I left the files in that state on the data card. Now I load OSCAR from a copy of the SD card that's a directory tree on my computer. So the trick was that I had to change all of the dates on one night back one day, and move them into the previous day's folder. And then I needed to separate out the files that were 12 hours into the future and change the times by subtracting 12 hours. I changed those in the file names and found the time stamp in the files and edited that, too -- those were all in cleartext. I didn't worry about the settings being off a day, and OSCAR reports that there aren't any settings for March 14th, and then it put the 14th's settings on the 15th, but I decided that I didn't care. :-)

I was pretty impressed with myself, for getting myself out of that pickle. Of course I did get myself IN to the pickle in the first place, LOL.

But I can learn from my mistakes. When I went to fix the clock on Sunday night, I didn't think to do it until after midnight. So I just left it alone and caught it at 9:30pm the next night -- setting it back from 10:30pm.

[Geer1]

Resmed days start at noon so that the entire night of data is counted towards a single day. If you take a nap or sleep in past noon you will notice that it splits the data at that time and shows up in the next days recorded data.

I thought you just couldn't overwrite data but they must have it so that the time cannot be changed if data has already been recorded on the day you try to change the time. I imagine it has something to do with how Resmed records session data or perhaps is to make sure compliance data is not affected by someone adjusting time setting. 

Resmed did not design these machines with the intent of accurate time keeping nor for the patient to know or care what the time is. Time is not displayed, it is not meant to be adjusted by the patient (hence being in clinical settings) and the data we view in OSCAR is not meant to be reviewed by the patient. Hard to blame Resmed for us trying to do something these machines aren't designed for.

[S. Manz]

Thanks for sharing that extensive response/experiment.
In our previous thread , we had come to the wrong conclusion that simply waiting an hour after the last use, for each hour that you want to set the clock back, is the solution. But that's not the case.
In fact you can not change the time "before noon" without erasing all the data first.

This is a serious issue when you fly east to other countries with several hours ahead in their time zone. (I travel to Europe a lot and I want to take my ASV with me because travel paps do not come in ASV model).

[Ratchick]

You could take a second SD card? Keep the ones from the different time zone on that, and your regular one just for when you're at home. Or copy the data off to your computer rather than deleting it.

[S. Manz]

I sure can. But that doesn't explain the problem with the clock.
I also have to sync Oximeter data, which is why I started looking into the clock issues when time changed over the weekend.

[Jeff8356]

Another option would be to keep your gear at your current home time while travelling abroad. Then no clocks to change.

[Ratchick]

It's because Resmed starts the day at midday, not midnight, as others have said. The 10th of June, for example, starts on 10th June at midday and ends 11th June at 11.59:59 am

Let's assume that you slept from 10 pm on the 10th June to 6 am on 11th June - this is stored on the SD card as data under 10th June. As you have recorded data for the 10th June, you can't change the time back to any time before the 11th June at midday. It doesn't matter how many hours have passed, it's related to what date and time are displayed on the clock. Yes, it can be an issue initially when going overseas, but it's not a critical issue, IMO. There are workarounds and it would only be an issue going one direction and is resolved the moment that it ticks past midday in your new location on that very first day.

In terms of the data card, if you need to turn the clock back further than midday, the only options I can think of are to either a) wait until it's past midday at your destination if you're flying west or b) use a separate card if you have to use the Resmed before it gets to that point and you can't just ignore it.

There is a third option, which is to correct it by using your timezone setting on your computer when importing the CPAP data into OSCAR. There is some wiggle room (at least on windows) to futz with timezones to alter the start time of CPAP data - I've used it when importing data from earlier in the year, pre-DST while we were still in DST - for the same reason as you mention, lining up Resmed data with my pulse ox data because it ended up an hour out of whack when I had to reimport the data. If you're interested in that workaround, I can let you know how I did it. But to be honest, I haven't tried it recently, and it's probably easier to just hold off until it's midday in your destination if flying west.

[Geer1]

When was the last time you changed ASV settings and how often do you change it?