watchOS 11.3.1 DST Bug

[BC2009]

This morning (March 9, 2025) we skipped the 2am hour due to the Daylight Savings Time change so that hour did not exist, but trying to set my alarm for Monday morning leaves me wondering when it will go off. All alarms set between 2:00am and 2:59am display as one hour later.

Problem is specific to Apple Watch. No issue on iPhone.

 

[goldmac2006]

This morning (March 9, 2025) we skipped the 2am hour due to the Daylight Savings Time change so that hour did not exist, but trying to set my alarm for Monday morning leaves me wondering when it will go off. All alarms set between 2:00am and 2:59am display as one hour later.

Problem is specific to Apple Watch. No issue on iPhone.

View attachment 2490462

Got the same thing on my end. My AW S6 alarms did not go off as scheduled due to the clock going forward from daylight saving time. But on my iPhone 15 Pro, the alarms go off as scheduled.

That is why I woke up at 7 instead of 6 today, I am on 11.4 watchOS beta 2 and iPhone on iOS 18.4 dev beta 2.

 

[BC2009]

Problem seems to have corrected itself the next day. Since March 10th has a 2am hour the alarm times automatically fixed how they were displayed.

Kinda annoying — you would think Apple would have unit tests for DST since they had all those problems back in iOS 7 and 8 and maybe 9 with iPhone alarms and DST.

 

[goldmac2006]

Problem seems to have corrected itself the next day. Since March 10th has a 2am hour the alarm times automatically fixed how they were displayed.

Kinda annoying — you would think Apple would have unit tests for DST since they had all those problems back in iOS 7 and 8 and maybe 9 with iPhone alarms and DST.

I recall that even if you rewind the calendar, it would cause boot loops on iPhones and iPads back then. For reference, what watchOS version are you running, and what series is your Apple Watch?

 

[BenGoren]

Seasonal time changes make exactly as much sense as buildings which number their floors “…, 11, 12, 14, 15, ….”

Mathematically, logically, there is no solution to these sorts of bugs. The flaw lies in the system that’s being modeled, not the model of the flawed system.

As you note, there is no such time as 2025-03-09 02:30. What’s the poor watch to do if you set an alarm for then? Logically, nothing whatsoever — but, of course, you still want it to make a noise in the middle of the night.

At the other end, the time 2025-11-02 02:30 will happen twice. Should the watch sound the alarm twice? Or just the first time, or just the second time?

Now, imagine the potential for chaos that this holds for, for example, an airline’s schedule. Even if (as is the case) everything internal uses UTC, it still has to get published for public consumption.

That’s something that Arizona gets right: no time changes, just permanent UTC-7 “Mountain Time.” We still get splashback, but not so much … mostly it’s never really knowing if it’s San Francisco or Denver that’s the same time as us, and whether the East Coast is two or three hours ahead.

Most of the world doesn’t bother with this idiocy — basically, just the US, Canada, and Europe.

b&

 

[BC2009]

I recall that even if you rewind the calendar, it would cause boot loops on iPhones and iPads back then. For reference, what watchOS version are you running, and what series is your Apple Watch?

watchOS 11.3 with a Series 7

 

[goldmac2006]

watchOS 11.3 with a Series 7

Ohhh so it wasn’t 11.3.1?

has your alarms been corrected yet?

 

[BC2009]

Seasonal time changes make exactly as much sense as buildings which number their floors “…, 11, 12, 14, 15, ….”

Mathematically, logically, there is no solution to these sorts of bugs. The flaw lies in the system that’s being modeled, not the model of the flawed system.

As you note, there is no such time as 2025-03-09 02:30. What’s the poor watch to do if you set an alarm for then? Logically, nothing whatsoever — but, of course, you still want it to make a noise in the middle of the night.

At the other end, the time 2025-11-02 02:30 will happen twice. Should the watch sound the alarm twice? Or just the first time, or just the second time?

Now, imagine the potential for chaos that this holds for, for example, an airline’s schedule. Even if (as is the case) everything internal uses UTC, it still has to get published for public consumption.

That’s something that Arizona gets right: no time changes, just permanent UTC-7 “Mountain Time.” We still get splashback, but not so much … mostly it’s never really knowing if it’s San Francisco or Denver that’s the same time as us, and whether the East Coast is two or three hours ahead.

Most of the world doesn’t bother with this idiocy — basically, just the US, Canada, and Europe.

b&

i would just want it to be consistent with iPhone

 

[BC2009]

Ohhh so it wasn’t 11.3.1?

has your alarms been corrected yet?

sorry it was 11.3.1. — the alarms corrected the next day

 

[goldmac2006]

sorry it was 11.3.1

👌🏻. So based on the original post were you testing something out if you set an alarm when the clock moved forward, then it automatically shifts forward?

I don’t think it was like that on my end when my AW6 ran the same version as yours in RC that time, but my alarms didn’t sound off at the moment it was supposed to be that night.

I may ask you a few more questions, so before we proceed do you also sleep track with your Apple Watch Series 7?

 

[BC2009]

👌🏻. So based on the original post were you testing something out if you set an alarm when the clock moved forward, then it automatically shifts forward?

I don’t think it was like that on my end when my AW6 ran the same version as yours in RC that time, but my alarms didn’t sound off at the moment it was supposed to be that night.

I have a regular alarm for 2:30 AM and I don’t think it went off as expected because I slept through it if it did. I tried deleting all of my alarms and re-creating them, which is what I posted in that video. The next day, all of the alarms that I had created showed the correct time, but they all showed incorrectly even after the daylight savings time jump had occurred so long as we were on the same day as the jump

 

[goldmac2006]

I have a regular alarm for 2:30 AM and I don’t think it went off as expected because I slept through it if it did. I tried deleting all of my alarms and re-creating them, which is what I posted in that video. The next day, all of the alarms that I had created showed the correct time, but they all showed incorrectly even after the daylight savings time jump had occurred so long as we were on the same day as the jump

👍I still slept thru my alarms too!