Talking about a specific day of the week

Question

In this exercise, there is the line "Le dimanche, comme il faisait beau..." which I assume is intended to mean "On Sunday (specific day), as the weather was nice..." but does not correspond to the teaching of the below lesson which states that "Le dimanche" means "On Sundays" (plural) and that "Le" needs to be omitted if you want to talk about a specific day.

Can you please clarify the discrepancy. Merci d'avance :)

Lesson link here: Using "le" with days of the week + the weekend (French Definite Articles)

ATTENTION:

You will NOT use le when talking about weekdays in a specific context (on Monday):

Mercredi, tu iras à l'école.

On Wednesday, you will go to school.

Mardi, je vais au théâtre.

On Tuesday, I'm going to the theatre.

Accepted Answer

Hi JaGGa,
It all depends on whether you are talking about a specific day, point of reference being now. 
lundi, je suis allé au marché = On Monday,I went to the market 
meaning last Monday, yesterday in this case.
jeudi, j'irai chercher les enfants à l'école = On Thursday, I'll go and fetch the children from school
In this case, it means the Thursday coming, today being Tuesday. 
In a story in the past, talking about that particular weekend, 
On (the) Saturday we did this and that = Le samedi on a fait ceci, cela
and on ( the ) Sunday we went home = et le dimanche nous sommes rentrés chez nous
If you just said, 
samedi or dimanche we would automatically think you were talking about in relation to now.
Hope this helps!

Answer

Bonjour Cécile !Je comprends maintenant avec votre explication. Merci beaucoup ! Le français c'est difficile !!! Trop de règles

Answer

Non.  Le week-end toujours mais Samedi!