Schedule for Annual Daylight Metrics

Hi @mikkel, there’s a few other posts along these lines but I thought this warranted a new one.

Why is the default schedule for Annual Daylight Metrics Weekdays from 8am-5pm?

Looking at IES LM 83 23 it recommends 8am-6pm 365 days per year for the sDA calc.

I wondered if this would be a reason to change the default to match IES, or if there’s another standard the current component is aligned with.

Best, Charlie

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Hi @charlie.brooker,

Maybe @chris can tell why the default schedule is 8am-5pm, if there even is a deeper meaning to it. As long as I remember it has been it has been the default.

I do not have any preference with regard to the default schedule. I think it should satisfy the majority of the users, so I do not mind changing it if necessary.

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I’m sorry to kick the can down the road but this was something that I copied from Legacy Honeybee and so @mostapha would know if there’s a specific reason for choosing this schedule.

If I had to take a guess at where all of this came from, I think weekdays from 8AM - 5PM was the default schedule that was built into DAYSIM, which predates the whole LM 83 23 standard. And I don’t think any of us could say why Christoph Reinhart chose that default schedule beyond the fact that it felt right to him at the time and I know from experience that he was pretty punctual in terms of teaching his classes early and ending his work day promptly at 5 PM :slight_smile:.

Long story short, I’m also in favor of changing the default to align with the LM standard, going from 8AM to 6PM every day of the year (regardless of whether it’s a weekend or weekday). The only thing that I don’t want to try to guess is whether a given climate file has daylight savings time in order to satisfy the “local clock time” part of the standard. I think we should just go with a default assumption of no daylight savings time since this is how most of the world operates and, to use the LM argument that “occupancy might change in the future,” I think that a lot of countries are similarly moving away from daylight savings time (I’m hoping we get rid of it in the US soon :crossed_fingers:). But, if someone wants to account for daylight savings time, I think it’s reasonable to ask them to build their own custom occupancy schedule.

Do you agree, @mikkel and @mostapha ?


Thanks for setting it all out Chris, personally I completely agree with that proposal.

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Yes, I think what you propose seems reasonable.

FYI, I have just changed the default schedule to what we agreed upon:

The update should be available with the LB Versioner shortly.

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