Author Topic: Standards for Handling Daylight Savings Time?  (Read 386 times)

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Offline havtrail

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Standards for Handling Daylight Savings Time?
« on: January 02, 2021, 05:48:51 PM »
Are there meteorology standards for the handling of Daylight Standard Time? Here on the U.S. east coast, by law we have a day in the spring that is 23 hours long (when Daylight Standard Time starts) and one in the fall that is 25 hours long (when it ends).

I know some will say that UTC time should be used, but how do you then present data to the public on local daily highs and lows, daily rainfall, and so on? You would have to convert UTC  to local time differently at different times of the year, to get midnight-to-midnight locally.

If you ignore Daylight Savings Time and pretend it doesn't happen, then for a good part of every year your data is off one hour from the general public's perception of what time it is, and when days start and end.

I save data logs at 5-minute intervals. It seems that to be understandable to the public, I will have a 23 hour day in spring with the logging times skipping from 02:00 to 03:05 (AM), and a 25 hour in fall where 02:05 to 03:00 (AM) get listed twice.

Many of us probably just use whatever our PWS software does, but I'm just wondering if there are general standards for how this is handled and presented to the public.

Rich K.
Onset HOBO RX3003 Cellular
https://weather.havtrail.com
NEWA pa_have

Offline CW2274

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Re: Standards for Handling Daylight Savings Time?
« Reply #1 on: January 02, 2021, 06:11:11 PM »
I know some will say that UTC time should be used, but how do you then present data to the public on local daily highs and lows, daily rainfall, and so on?
For an official capacity, UTC (or as I say "Zulu") will always be used, as is with just about anything that is potentially "global". When it's a "local" thing, local time is normally used, but UTC may be used as well during AFD's and the such.