Many of our devices, such as the HomePilot, the Troll Comfort devices, the RolloTron Comfort devices or the HomeTimer use the astro function to control the roller shutters.
Here, dawn and dusk are not measured, but calculated with the help of the location and the date.
As a basis for calculation, however, not the sunrise or sunset is used but the so-called civil twilight. The calculated times are approx. 30 minutes before sunrise in the morning and approx. 30 minutes after sunset in the evening.
You can adjust the calculated times in the settings of the devices by an offset, so that in the evening with an offset of -30 minutes approximately meet the time of sunset.
Note: If you want to use the astro times all year round with the time switches and RolloTron devices, please set the switching times relatively early for mornings and relatively late for evenings, as the switching times define the maximum range.
More information about the civil twilight can be found in the following Wikipedia article
We also provide a small astro tool with which you can plot the twilight curves at your location. The calculated times of this tool may differ from those of your device by a few minutes.