SleepyHead/Daylight Savings Time

[Sheepish]

Similar weirdness here. On Sunday morning after I woke up around 8, I set my DreamStation back one hour. Now:

• All previous sessions for the past several months show as starting and finishing 1 hour earlier than they did in reality, e.g., if  went to bed at 12:15 AM and got up at 6:30 AM, Sleepyhead now says i went to bed at 11:15 PM and got up at 5:30 AM
  
• However, last night's session, from after I the time back 1 hour, shows the correct times in Sleepyhead.
  

Any way to fix this?


Edit: Actually, it's weirder. I just noticed that the times on the graphs are changed to one hour earlier than reality, but the time display at the bottom is the correct time. In this screenshot, compare the time on the graphs where I dragged the mouse over the timeline where it says about 6 minutes past midnight (00:06), but at the bottom it says about 6 minutes past 1 AM (01:06).
 ¿Qué pasa? :

[CB91710]

The missing day ...

Odd that you missed a day.

I changed mine and my wife's machines before going to bed last night and I'm not missing any days from either of them.

Now that they are on "standard" time I'll probably leave them alone in March.

[CB91710]

Similar weirdness here. On Sunday morning after I woke up around 8, I set my DreamStation back one hour. Now:

• All previous sessions for the past several months show as starting and finishing 1 hour earlier than they did in reality, e.g., if  went to bed at 12:15 AM and got up at 6:30 AM, Sleepyhead now says i went to bed at 11:15 PM and got up at 5:30 AM
  
• However, last night's session, from after I the time back 1 hour, shows the correct times in Sleepyhead.
  

Mine is the same.

If I go back to last March, the times self-correct, so I'm assuming it is because of the way the data is stored in Sleepyhead compared to the PC clock.
All of my summer data is "early" by an hour.

It doesn't really matter though....  there's no pressing need to "fix" it.  All that matters for compliance is hours and days used.  An hour, two, or even 6 hours "off" makes no difference.
Correct times are mainly helpful if you are attempting to connect an event on the chart to something that happened when you were using the machine and mentally noted the time.

[srlevine1]

The missing day ...

Odd that you missed a day.

I changed mine and my wife's machines before going to bed last night and I'm not missing any days from either of them.

Now that they are on "standard" time I'll probably leave them alone in March.

I think figured out the issue. I went to bed at 4:30 a.m. and slept over the 12:00 p.m. ResMed cut-off, therefore I had a partial day recorded. When I set the clock back the next day, it wiped the partial day.  

Of course, I did not think to back-up my SD card because my computer is always backup on a daily basis. Live and learn.

[Sheepish]

Similar weirdness here. On Sunday morning after I woke up around 8, I set my DreamStation back one hour. Now:

• All previous sessions for the past several months show as starting and finishing 1 hour earlier than they did in reality, e.g., if  went to bed at 12:15 AM and got up at 6:30 AM, Sleepyhead now says i went to bed at 11:15 PM and got up at 5:30 AM
  
• However, last night's session, from after I the time back 1 hour, shows the correct times in Sleepyhead.
  

Mine is the same.

If I go back to last March, the times self-correct, so I'm assuming it is because of the way the data is stored in Sleepyhead compared to the PC clock.
All of my summer data is "early" by an hour.

It doesn't really matter though....  there's no pressing need to "fix" it.  All that matters for compliance is hours and days used.  An hour, two, or even 6 hours "off" makes no difference.
Correct times are mainly helpful if you are attempting to connect an event on the chart to something that happened when you were using the machine and mentally noted the time.

This may not have any effect on my OSA, but it will exacerbate my OCD. 

[pholynyk]

>>>This may not have any effect on my OSA, but it will exacerbate my OCD. Blink<<<

Welcome to the programmers' world. There are a lot of complexities in doing time stuff, and having three (four!) different time clocks running for one piece of software --- wall clock, computer clock, and CPAP machine clock (and the oximeter clock!) --- make for lots of synchronisation issues - and they show up especially when the clocks change at spring and fall.

[Sleeprider]

Sleepyhead has an option to correct for DST. Perhaps if change the machine time, you end up with a double correction? I think it is not very important to correct for DST on the machine, or especially to correct for travel between time-zones. The data does not change except for the time-line, which is not something I am concerned about when I review data.

[Sheepish]

Found where to set SleepyHead for a DST Zone (under File | Edit Profile), and it was already checked.



Unchecking it and restarting SleepyHead or then checking it again and restarting SleepyHead changes nothing -- the discrepancy is still there.

Maybe write it off to a programmer's miscalculation, but does this not gnaw at your OCD?

[pholynyk]

The difficulty is that the waveform data is continuous, and of the proper duration. The event flags are (evidently) time stamped by a clock which isn't changed during the session. The local wall clock time, however, is folded, or reset, back on itself (or jumped forward, in spring). The labelling of the time line gets messy visually, and horrible from a programming point of view... Finding a data plotting program that displays local time properly, even if the data is stored by UTC, may be a problem.

I vote we drop Daylight Saving Time; it would make programming so much easier.

By the way, I'm not sure if Respironics machines (which use UTC) are affected by this. I think they are.

I thought you couldn't set the time on Respironics machines, but Sheepish says he set the time on his DreamStation. Help, please!

[Walla Walla]

You can set the time by half hour increments on the DreamStations. You can't adjust for drift of say 15 minutes though.