Daylight Saving & Standard Time

[Buford T. Justice]

Since Daylight Savings Time goes into effect Sunday morning, is there anything that needs to be done to Cumulus to not mess up data? It would seem the data would just jump ahead an hour so an hour of time would be missing right?

For Standard Time, it would seem it is best to close Cumulus during the time change, but what about the display data? Would that data mess up Cumulus logged during the time change?

[RayProudfoot]

Just leave Cumulus running. There'll be a gap of 1 hour in your data but nothing untoward will happen.

Clocks here go forward in 3 weeks.

[steve]

Yes, it's always best to leave Cumulus running if possible when the clocks change. You can then guarantee that you'll have a well-defined set of data. If it has to use logger data, you end up with differing results depending on the type of station and whether it timestamps its data, and when you close Cumulus and start Cumulus up again. It's not hard to work out what happens in the case of a Fine Offset station with logger data, given that it doesn't timestamp its data, and Cumulus always tries to backfill from the time it was last closed down.

[Buford T. Justice]

Cool. Thanks.

[krmidas]

It was interesting to see the graphs flat-lining during the "discarded hour" last night, as we moved our clocks ahead in the US.

I've wondered how Cumulus handles turning the clocks back in the autumn. Are there two sets of readings between 1:00 AM-2:00 AM? How does Cumulus handle this extra data? I assume statistics like wind run get skewed by the extra hour.

-Tom

[steve]

I've wondered how Cumulus handles turning the clocks back in the autumn. Are there two sets of readings between 1:00 AM-2:00 AM?

Yes.

How does Cumulus handle this extra data? I assume statistics like wind run get skewed by the extra hour.

Yes, that day will have an extra hours worth of wind run. Values which are calculated based on the time they were recorded will also get affected, like rain in the last hour etc.

It's not ideal, but I'm not aware of any software which handles it any better. Anyone for whom this is an issue should be running their station and their PC on 'standard' time throughout the year. I know that many 'serious' weather enthusiasts in the UK run their PCs and weather stations on GMT year round, and always report in GMT.

[tjaliwalpa]

Today was the end of daylight saving in South Australia. There were no apparent dramas with Cumulus. I have the PC running 24/7. The most interesting thing involved the graphs produced by Cumulus. Here are a couple of them: