LBT 1.4.0 Daylight Savings Time, is it applicable in Annual Daylight simulations?

Many countries switch clocks on the last Sunday of March, and then switch back on the last Sunday of October. This should have an effect on the HOYS considered by the simulation when one sets an annual occupancy schedule e.g. 8:00 - 18:00, as it will affect the .epw irradiance values that will be used to model the sky for each hour timestep. For example, if on March we turn clocks 1 hour forward, the “actual” occupancy will turn into 7:00 - 17:00 for the DST period, and so different HOYs would need to be considered.
Is this considered by the Annual Daylight simulation, so that the simulation will consider the actual occupancy period (since people switch their clocks as I mentioned)? If not, is it possible to “enable” this for Annual Daylight simulations?

Hi @IasonBournas ,

Daylight savings time is not accounted for by default in the annual daylight recipe and, if you want to account for it, you have to do so with a custom occupancy schedule. Here’s a sample for how you can make one of these and apply it to an annual-daylight simulation:


annual_daylight_dls.gh (92.8 KB)

If I had to cite a reason for why daylight savings is not the default, most of the world’s population doesn’t use it and it’s not a practice that’s really growing these days. It seems like we are just about to do away with it in the US now.

1 Like

Alright! I was using a lot more components for this, the way you proposed with the seasonal schedule looks much better, thanks!