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by maxmax_ 2096 days ago
> The duplicate/missing hour around DST switching can also be quite annoying.

Oh yes. I used to work for company which produced medical software which continuously recorded patient data. Those duplicated or missing hours were always the worst and error-prone use cases.
1 comments
Mountain_Skies 2096 days ago
More than one vendor has become rather upset when I've demanded that they handle those situations appropriately. But much of what I do involves automation so I don't want any surprises or in this situation, two known exceptional cases that need to be accounted for. Also I find this to be a code smell, like brown M&Ms in a contract rider.

Don't know if they've fixed it but when I had a Fitbit, they never was able to get these DST change over events handled correctly. What's worse is that their website and their app both handled the change over in different ways, both wrong.

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CodesInChaos 2095 days ago
What do you mean by handle appropriately here? This is one of the cases where I'd simply store UTC and display the (sometimes ambiguous) local time in the UI.
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Mountain_Skies 2095 days ago
The problem was that they weren't storing events in UTC but were using local server time instead. They had no explanation for what would happen during the switch from daylight time to standard time but couldn't rule out the possibility of out of order events happening due to it.
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