On daylight saving time change

Last night we change hour for daylight saving time (at 2:00 it would be 3:00).

So I made a simple test to set an alarm at 2:10

  • At 1:59, clock jumped logically to 3:00
  • no alarm
  • At 3:10, alarm rang (in fact I had turned it off and back on, but that has no influence)
  • I set an alarm at 3:15, of course it rang
  • I set a new alarm at 2:20
  • It rang at 3:20

Conclusion: Clock app "replicates" the alarms between 2:00 and 2:59 into 3:00 - 3:59.

Which is great, not to miss any.

Question: Is this specific to Clock app or a more general system behaviour for all time events ?

If so, there may be a side effect:

  • I set an event A to turn On a light at 2:45
  • And set event B to turn it Off at 3:15
  • Then B will occur before A and the light will remain On

There is no perfect solution ("warping" 2:00 - 2:59 into a minute at 3:00 would creates other issues).

Extra question: What happens on winter time ? Will alarm ring twice at 2:10 ?

On daylight saving time change
 
 
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