Evening Time is Reading Time

In Utrecht, Holland, I noticed these signs down BOTH sides of one street.  Each sign has the phrase "Evening Time is Reading Time" in the same place. But the first one has a little black window shade with a circle pull at the very top. The text is black on a white background. As you walk down the street, the progression of the signs is such that the black window shade comes lower and lower, as "evening" falls, and the text turns from black on white to white on black. It culminates in the shade fully down, and the text all white.

What I had NOT realized, or thought about, was that the flip sides of the signs had graphics too. These graphics depicted individual occupations. More on that further down.

This is a close-up of the first one.

Intrigued, naturally, I went on line. I LOVE the internet because I have no unanswered questions anymore. Here's the deal:

The Centraal Museum in Utrecht organized the "Night Rules—Night Lines" exhibition in 1991 for which contributing artists were asked to introduce a short text in neon light into the public space, which connected to a specific location in Utrecht's center. The works would then be viewable only at night, as they were connected to the street lighting. American artist Allen Ruppersberg surveyed the residents of this street (Korte Smeestraat) and noticed they all seemed to have interesting and diverse occupations or hobbies. He then created personal signs for about twenty residents on this street, each with an old-fashioned image borrowed from ads from old magazines, depicting what that person did for a living (or their hobby).  So those were on the FLIP side of these signs. I saw them and thought they were just vintage ad/posters. I hadn't realized their meaning. So cool. 

Here's where I learned this: 

https://indebuurt.nl/utrecht/utrechters/utrechtse-mysteries-het-verhaal-achter-de-borden-in-de-korte-smeestraat~38082/

And here are some shots from that website showing the other side of the signs.

Gotta love public art that makes you think!