Exsate caculator said was the right time last week. I think the image above was a little too early and the sky had some clouds to block the true blueness of the sky at that time of night.
This one was more what a blue hour image looks like but it's too light.
The blue hour isn't really an "hour" at all. In reality, what photographers call the blue hour really only lasts about 20 minutes. The blue hour lasts approximately 20 to 30 minutes just after sunset and just before sunrise. The exact time of the blue hour will vary with location and will change depending on time of year and things like air quality.
So I waited... thinking that it wasn't dark enough and I got this...
And this one, of my garden shed with a nice reflection in the small window.
So I used the only outside, "lit at night", model that I could find.
And then, faster than I expected, the sky was too dark... so I just call these "night shots".
and... "solar light in the hollyhocks".
It's a good chance that I may have caught one blue hour images in Germany two years ago and didn't even know it.