Daylight Savings Time (DST) - Graph of BG

I don’t have an issue that has to be resolved. I am just curious.

Although I wasn’t awake at 2 AM, I looked at my 24 hour BG graph yesterday morning and expected to see a 1 hr gap in the numbers as we moved to DST at 2 AM. My BG is plotted every 5 minutes. I would have expected it would be plotted at 2 AM and them 5 minutes it later I would see it plotted at 3:05 AM. But I see no gap. Why not?

I don’t know what you are using… but with my G6 and “official” G6 receiver, I have to manually roll the time forward an hour. In fact I didn’t do that until just a minute ago when I read your message on this board!

I know that the transmitter has its own clock, and it is impossible to get another day out of a sensor by setting receiver time back one day. I know this because I tried! The sensor life is determined by its own transmitter clock and not the receiver clock. So both receiver and transmitter have clocks. I guess the receiver sends its time to the transmitter at least occasionally.

Now there’s another layer if you upload to Dexcom clarity. I have seen for a 3 hour backwards time change (flying to west coast) that for 3 hours I had two sets of data on that.

I checked my Dexcom graph from yesterday. The one hour gap occurred starting just after I got up. That is when I changed the time in the Dexcom G4 receiver. It serves as the basis for my Loop system. Loop automatically changed time when the phone time changed but I did have to update my pump time through the Loop software when I got up.

I use G5, a G5 receiver and Xdrip on my phone. Since you brought up Clarity I just checked yesterday and I saw a gap between 3:13 PM and 4:18 PM so I guess that is where they put the gap. But it is different on my phone where I use Xdrip. I see no gap at all. But, thanks, that at least explains Dexcom and Clarity. I think I will need to bring this up to Xdrip users.

I display my Libre sensor on my phone. Yesterday morning my graph line showed an icon at 2 am that indicated the time change had occurred.

Your dexcom app on your phone??

Not Dexcom, Libre

Ok, thanks

I believe the 5 minute readings are recorded/stored with gmt time set by factory. The display time is for user, based on settings.

When I have downloaded data, I see the bg value and 2 date/timestamps for each bg reading, one is GMT, other is local.

The display for the one hour DST change probably repeats same reading 12 times for the missing hour, based on when you updated receiver/app.
What time did you update receiver, or if phone, did it automatically adopt phone local time?