Month: January 2026

19’2026 (2026-01-19) – First day of the week

Posted on by What did you learn in School today ?

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Today, I learned about:

Have you ever thought about why the week contains seven days, at least in Western cultures? In Western cultures, it seems that 7 is a holy number used in many contexts, although Asians many times consider it a number that brings bad luck. More about that can be found in reference #1, under the heading History.

As I told you in my 10-year post on 9’2026 (2026-01-09) , during the upcoming posts I will review some of the older posts, and in fact, in the very second post on 10’2016 (2016-01-10), I mentioned that according to the international standard ISO 8601:2004, there is a normalized manner of writing dates in the format of “YYYY-MM-DD”.

But there are many more things to be considered in that standard, e.g. it states that the first day of a week is a Monday. However, you may live in a country that has the tradition of using Sunday as the first day of the week. Where I live, in Brazil, that is the normal way of thinking. And as a consequence, the days in Portuguese are named as Domingo, Segunda-feira, Terça-feira, Quarta-feira, Quinta-feira, Sexta-feira, and Sábado. You probably understand the meaning of what Monday through Friday is in Portuguese, but where does it come from? The Portuguese word “feira” means a sort of street market, where you can go and buy fruits, vegetables etc. In ancient Portugal, Sunday was the first day of the week with such a market, Monday was the second day, thus Segunda-feira, etc.!

Today’s header photo was taken in Schwerin, Northern Germany, by my friend Alfredo Acosta. It shows the castle built in the 12th century, replacing the ruins of a former slavic fortress and that is also the birth date of the city of Schwerin. More about Schwerin can be found in reference #2. (Alfredo’s wife, Laura Ponce, contributed with a photo from another German city, Greifswald, in my post 151’2025 (2025-05-31). Thank you both for your valuable contributions!

That’s what I learned in school today! 

Ref.:

1: Week history

2: Schwerin

*: What did you learn in school today?

9’2026 (2026-01-09) – 10 YEARS/ÅR/ANOS

Posted on by What did you learn in School today ?

Today, I learned about:

Today has passed exactly 10 years since I started this blog, 9’2016 (2016-01-09) , and of course I am very grateful to all of those who have followed me this far! If you are a recent follower, then I suggest that you look at this post, 14’2017 (2017-01-14) , where I describe how my friend Tereza Vieira gave me the idea. Once more, Tereza, I am much obliged to you!

During the upcoming posts I will also give everyone the chance of discovering which posts and their respective contents that have been most appreciated during these years and now can join Tom Paxton, Pete Seeger, and me for this Tin Anniversary! (See reference * below)


That’s what I learned in school today! 

Ref.:

*: What did you learn in school today?