This could be multiple suggestions but I'll start out with my issue:
I live in the midwest and Sunrise and Sunset times don't reflect how much light is outside. In the summer, sunrise could be 6:00am but it is light outside by 5:30am, yet in the winter sunrise could be 7:50am and it doesn't get light out until 8:30am. Any logic I use to turn lights on or off around sunrise or sunset now has date conditions to apply during certain times of the year. In looking to simplify this, I decided to make sunrise and sunset offset variables and then I only need to change the variables in one place and each rule could pick them up.
This is where I ran into my second issue - I can use the variables in time offsets in wait commands and trigger events, but I can't use the time variables inside of IF / THEN statements that call on conditions (these have to be set inside each condition manually).
Of course after typing all this out, I do realize the best thing to do would be to get a light sensor to place outside and bypass all this logic. I do think variable offsets inside time conditions would still be useful for others, and/or a seasonal mode might be useful as well.
An other option that I can think of is to set hub variables where you store the Sunrise and another for the Sunset times. A single rule could update both daily during the night, and then it could be used as-is by all your other rules.
That's not a bad idea - I was storing the offset variables, but you make a good point to just store the updated time as the variable instead. I'll go give that a shot.
In my research today, I do think I might have identified a hard-wired motion / temp / luminance sensor that would work. But now I have to figure out where I could install one.
I changed the variables to Date/Time and have a rule that runs nightly to update them. Tried it out and seems to work on my rules. Thanks for the idea!
I was looking at the HomeSeer HS-FLS100 (Gen 2). I like the idea that if it gets stormy out and dark in the middle of the day, it could trigger rules to turn on some lights.
I don’t have a HomeSeer myself, but anything that will consistently report lux values should do the trick. Before I got my Tempest, I used a Zooz sensor that was close to a window and could detect illuminance. Worked well enough!
I read your post and wonder if you could attack this differently. I pull Lux values from a local city hall weather station a short distance away. Can you use Lux/Luminance? OWM can provide that...
I was going to suggest similar. I have multi sensors externally and have rules that set hub variables to true when the lux value passes a certain threshold. That hub variable is then used to turn lights on/off. It’s handy to have a sensor on each elevation of the building as the areas are at a different level according to the position that the sun rises and sets. Using lux values also gets around changes caused by weather that sunrise/sunset with offset can’t account for.
For what I'm looking to do, multi-elevation lux sensors would be overkill (at least for now, ask me again in five years).
I do have a spot outside that will work - an electrical box that has a free port on the bottom that I can unscrew and attach the HomeSeer, I just won't use the switched function of it. The location is pretty good; north side of the house and it will get morning sun but be shaded the rest of the day. Ideally I will want it under cover, but that is a slightly larger project for another day (but that is in the works).
