Time stamp out by 8 hours, ResMed AS11 and Linux

[mgdapnea]

Context
Oscar 1.4 on a Fedora 37 (Linux system)
Install source for Oscar: johanh/oscar on Fedora copr
CPAP Machine: ResMed AS11
Data source: SD Card

Analysis
I entered the clinical settings on the AS11 and checked the time, GMT-8.
The commands 'date' and 'timedatectl' verify that the local time is correct, the date is correct, the timezone is correct, and the GMT offset is correct.
The time and date displayed in the taskbar are correct.
Oscar's Local Settings in the User Profile show the time zone as GMT-8 Pacific Time USA/Canada.


Problem
Uploads from my SDcard to Oscar work correctly, but the charts have time stamps that are always 8 hours too soon. For example, last night, I began my therapy at 9:00 p.m., or 21:00 hours. Oscar shows that recording begins at 13:00 hours.

Data Verification indicating issue is with Oscar
If I upload the same data to sleepHQ, the timestamps are correct.

Question
Are there any Linux or ResMed or Oscar gurus that could provide some insight or suggestions?

Attachment
One picture from last night showing the beginning of the Flow Rate...

[Jeff8356]

mgdapnea, Welcome to Apnea Board!

Do you happen to have the "CPAP clock drift" set in OSCAR preferences?

Open your profile, then Preferences > CPAP
The clock drift should be all zero's.

[mgdapnea]

Yes, they are all zeros...thanks for responding.

[Crimson Nape]

Has this always been the case with OSCAR on your Linux box? I know that a Linux system sets the PC's clock to GMT and performs the time offset separately. A Windows system sets the PC clock to the current time based on the declared timezone. I have no idea what a Mac does. This past week, there were several tzdata updates issued by the Linux foundation. Have you checked for updates?

- Red

[mgdapnea]

I don't think it is a Linux issue. Yesterday, I just upgraded my system from Fedora 36 to Fedora 37. I installed Oscar subsequent to the upgrade. So, all time settings/packages will be current.

Here is the output of several time commands. Everything seems in order...
[~]$ timedatectl
               Local time: Sun 2022-11-20 09:28:53 PST
           Universal time: Sun 2022-11-20 17:28:53 UTC
                 RTC time: Sun 2022-11-20 17:28:53
                Time zone: America/Vancouver (PST, -0800)
System clock synchronized: yes
              NTP service: active
          RTC in local TZ: no
[~]$ date --utc
Sun Nov 20 05:28:59 PM UTC 2022
[~]$ date
Sun Nov 20 09:29:03 AM PST 2022

The tzdata package is described as: This package contains data files with rules for various timezones around the world. But, as you see from the output of the commands, there is no problem with my timezone, nor with the GMT offset.

Murray

[Crimson Nape]

H-m-m-m-m.  Since I don't have an AS11 for a fair comparison, I just imported the same AC10 data on both a Windows and a Linux box to different profile names on each one.   All the timestamps matched.  This just leaves the AS11 as the variable.  The only other thing I can think of at this point, it to run a checksum on the OSCAR install file that you used.  I don't anticipate anything, but I've seen odd things happen from a corrupted download before.  

If you need a comparison value, please advise which flavor of the Linux OSCAR you are using.  Providing the wrong version's value is believed to have caused heart attacks in the past.

- Red

EDIT:  I just went back and read your initial post, which answers my last section of my post.   I don't have any Linux boxes using a RHEL flavor of Linux.  All mine are Ubuntu/Debian based.  Sorry!  :

[pholynyk]

On the SD card there is a folder called Settings, with a file named CurrentSettings.json. It is a single line, which is annoying. You can prettyprint it with python3 -m json.tool CurrentSettings.json

Then look for "TimeZoneFeature" and see if the offset reported there is the same as that displayeed in the Clinician's menu.
(There have been some reports where they have not matched.

My Linux box is Debian, and it seems to work correctly with the contributed AS 11 files that I have looked at.

[mgdapnea]

Thank you,

That was a quite helpful suggestion as I had not looked at the settings files on the SD Card.

Here is the snippet for time zone...

"TimeZoneFeature": {
                    "TimeZoneOffset": "-08:00"


So, unfortunately, that appears OK.

[mgdapnea]

I made a small step to resolving this issue. Initially, I did a manual file copy from the SD card into Oscar's data folder. I decided to purge all my data, not my profile, and import the data correctly using Oscar's 'File/Import CPAP Data Card' menu. I saw that the data gets massaged a bit and placed into my profile directory. Unfortunately, the time stamp is still off by 8 hours. I guess I may end up blowing away my profile and starting again.

[pholynyk]

I'd like to look more closely at your SD card data. Please use OSCAR's Help->Troubleshooting->Create zip of CPAP data card

Please include your forum name in the zip file name, and upload it to https://www.dropbox.com/request/REp6AH7LCGyeOcXfOokH

Thanks