ResMed Day is Noon to Noon, Right?

[upsman]

This may be hard to explain, but I'm having a discussion with someone who claims that the ResMed day is from 11 pm to 11 am.

Now I know the machines do not correct for DST and he is living in FL like me and on EST so his machine could be an hour off. Given this, TECHNICALLY he would be correct in stating what his day is....or would he? If you change the time in your machine incorrectly to 3 hours off the actual time, say 11 pm to 8 pm, then wouldn't this make the day for him 8 pm to 8 am? 

Does the machine calculate the noon to noon based on your time zone? I guess I'm trying to explain this to him, but I'm not sure how or why ResMed uses the noon-to-noon parameter. 

Does this make any sense at all? 

[Jeff8356]

For the AS10:
It's a 24 hour window.  So they usually say "Noon to Noon" providing the machines clock is set correctly to your current time.  So if you set the clock in the machine back three hours, and stayed in your time zone, the machine would still start its new day after that 24 hour period which would now  be 9am.  The machines do not adjust themselves for DST.

I'm guessing Xpap manufactures determined that the average person sleeps at night and works during the day.  So doing the day change at midday would be most practical.  Not accounting for those that do odd shift work.  There are users who have purposely set the time differently to better match their odd work schedule.  So their ResMed day may be from 10pm to 10pm.

The AS11 is different though.  IIRC it uses a time zone offset to set the clock.  East coast US is -5 UTC right now.

[upsman]

Thanks. That clears it up a bit.
So, if his machine clock is set incorrectly, his 24 hour period could very well be 2300 to 1100. 

This guy is one of those "know it alls" so any discussion requires an exact explanation. 

[Ratchick]

Yes, noon to noon. Always noon to noon. At least with the S10. I'm guessing his clock is set wrong on the machine. Having the computer time zone wrong when importing data into OSCAR can futz the times up when you change it back to the correct one, but no. Resmed machines go from noon to noon, based solely (afaik) on the time that was set in there. If it is causing issues, then your friend can change this, but he will have to make sure the date is correct.

If going forward 13 hours gets the correct date and time, then you can do that any time.
If you need to go backwards 11 hours, you must wait until past 10 am and make sure that no data is recorded onto the machine during the time frame from 11 pm in your timezone (i.e. the previous 11 hours of real-time). Otherwise, the machine will refuse to let you go back because it would screw up a days' data and it can't be split. The easy way to check - look at the clock on the CPAP

[pholynyk]

>>>So, if his machine clock is set incorrectly, his 24 hour period could very well be 2300 to 1100.

NO! It's always 24 hours; 2300 to 2300 the next day.

The AS11 adds another wrinkle, not yet mentioned. You must clear all stored sleep data (not the settings) before you can change the UTC offset. SO basically, as far as I can tell, you want to set your UTC offset to the standard time offset in your home location, and never change it, even while travelling across time zones.

[upsman]

>>>So, if his machine clock is set incorrectly, his 24 hour period could very well be 2300 to 1100.

NO! It's always 24 hours; 2300 to 2300 the next day.

Right. I know this. That was a mistype.
Should have said 2300 to 2300 as you noted. 

[cathyf]

The AS11 adds another wrinkle, not yet mentioned. You must clear all stored sleep data (not the settings) before you can change the UTC offset. SO basically, as far as I can tell, you want to set your UTC offset to the standard time offset in your home location, and never change it, even while travelling across time zones.

Looking in my crystal ball I'm seeing that a great future OSCAR feature will be some tools to disentangle the mess that an AS11 is going to make out of a traveler's data...