The Sunrise/Sunset feature takes the specific location of the devices based on your phone, and creates a year long schedule based on the sunrise and sunset that will automatically change the on/off times throughout the year.
Before you start programming, here is some information about how sunrise/sunset works.
"Location Settings" ON in Phone/Tablet. Sunrise/sunset is programmed based on the location settings on the phone or tablet that you are using for programming.
Make sure that you have locations settings ON in your phone when you are programming a schedule. If it is OFF, then sunrise/sunset will not work.
As a quick point of fact, schedules run from the memory on the device, not from the app. The app is used to program the device, and then schedules are kept on the memory of the device. This is why schedules run whether the phone is near the device or not.
To enable the feature:
On the schedule screen, choose the sunrise or sunset buttons to select the turn on time.
Enable the days of the week to apply Sunrise/Sunset scheduling.
Save and name your schedule.