Daylight savings in Layout?

Is there now daylight savings in Layout? I have some viewports for diagrams of sun/shadow where I control shadows inside Layout to reduce the number of scenes imported. When I change the date (a model geolocated in Norway, and we have daylight saving from late march until late October) then the time of day also changes. So when I have a viewport set to 21.march (in Layout, overriding the scene), and change that to a corresponding date in April, one hour is automatically added to the time of day.

if I correct the time of day to the same as In sketchup, (with the same manual override to correct for daylight savings) then I get the same shadows in both Sketchup and Layout, so clearly there is no daylight savings in the shadow calculations). So its just that the time of day changes one hour when I cross the daylight savings start date when changing the date. The same does not happen when I change dates within the daylight savings period.

I went to post the same thing and found this thread…

Why is this so confusing!?
It has the potential to lead to serious legal issues due to errors.

Daylight Savings (and timezones eg +12 and +13 where I am) are confusing enough… " do clocks go forward…or back…what does “foward” mean?" ( we are living in an error of digital timekeeping)

Can we please just get a “daylight savings” checkbox that applies it, or some other easy indicator to show that it’s applied…like somethign relating to our location field that says “Auckland +1300 (Daylight Savings Time)”

Getting accurate shadow times of day is really critical for all sorts of projects.
If SketchUp want to make shadow studies even little bit easier, then we could have something like “Equinox” and “Solstice” applied automatically, too.

It is not that easy. Daylight saving time is about politics, not astronomy. The start and end dates vary by region, and in some parts it is not observed at all. The same can be said even about time zones.

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I remember a version of sketchup having daylight savings as a tickbox . Around version 4 maybe? Then the feature disappeared.

Of course it puts some responsibility on the developer to get them right, but is not like there are 100 different versions of daylight savings around the globe.

Time zones, when they are illogical will anyway mess up your sun/shadow diagram. Like in my country, that stretches different geographical time zones is it still (politically) decided to keep the time ( the clock) the same across those zones.

I guess from the developers point of view it is important to get the message across that the user will have to set it up correctly to get the right result. A half-automatic version, with automatic daylight savings but not corrected for illogical time zones will easily send the message that you dont have to think for yourself.

The main issue for me right now is the inconsistency.

Layout is actually correct…it understands when daylight time applies and appears to adjust the time value accordingly, based on Geolocation data. It’s a helpful feature… but poorly implemented.

I think that its wrong to adjust the time value because that’s confusing. 9am is not 8am. LayOut should instead change the UTC value - however there is no visible UTC value in LayOut.

SketchUp is different…it ignores daylight time completely. So, if I change the date from Winter to Summer I have to then manually alter the time value by adding one hour, or, I have to change the UTC value. The correct approach woudl seem to be that I should change the UTC value - but then what happens in LayOut? Woudl LayOUt then add one more hour (making it +2 hours?).

The data about when daylight savings time occurs in any given place can’t be too difficult to source. PreDesign must use accurate data, right?

But SketchUp doesn’t even need to do that; all we need is a checkbox that we can manually “check” when we want to apply daylight savings time. SketchUp would then change the UTC value by +1hour and adjust the shadows accordingly, while keeing the Time value the same.
And this has to be consistent within LayOut.

I kind of agree with this :slight_smile:

Anyhow: making a scene for every shadow study ( I can have 15-20 of them ) would make my sketchup model very busy on that front.

So I set my dates and time of day in a big table of shadow studies, multible overrides from the same scene, inside Layout.

So for me, inside Layout is where all the shadow controls need to be.

Yes, I do the same, mostly. Shadow controol in LayOut is simple.

I do seem to need to create anew LO documnet with lots of views and pages custom to each shadow study - seldom am I able to recycle the template from a previous project since the scale, view, times of day, location, etc all change a little bit.

I also produce short scene animations of shadow movement, and I send the model to a raytracer to acheive the most accurate shadow/sunlight.