Division words are words that divide eg: day, evening morning and are masculine in French. ...Tomorrow is the day. Day is used to divide a time period. They are all masculine.
Duration words extend for a period of time. eg: day, evening, morning, are duration words and are all feminine in French.
Very confusing, right? Here is how it works.
Tomorrow morning ...le matin. All morning....la matinée
that day ....le jour. hot day ...la journée
If you say you are going for a walk in the morning, you are not segmenting that morning from another. You are describing something that extends for a period of time.
If you say you got here today, you are dividing the day (le jour) from other days that you might have arrived. If you say the day (la journée) was hot when you arrived, you are talking about something with duration.
If you say ...the day (le jour) of the event is Saturday, that is division.It separates the day from other days, even other Saturdays.
If you say the day (la journée) is Saturday, that is duration. It is Saturday all day long.
La journée est calme....describes duration therefore requires that the feminine form be used.
But the thing is, you may very well go for a walk the next morning. You may go for a walk every morning. There is nothing in saying... I am going for a walk in the morning.... that divides the morning from other mornings. What it does say is that you are going to do something in the morning. Something that doesn't necessarily separate it from any other morning. But it will take time to do it. The sentence will contain nothing about dividing it from other mornings when you walk. It will describe something that takes time but does not separate time.
The distinction seems leaky and tenuous. If I am going for a walk in the morning, it will not be the following morning morning that I do so, nor the previous. That seems a division - or delimiter - to me. Language seems somewhat lacking when it comes to capturing this linguistic phenomenon. That is to say, I can find examples that seem to share both characteristics of division and of duration. Thanks for your response northernguy, it has been very helpful. I shall consider and test it further.
"Jour" is used in contexts where the word "day" is a measure word. For example, if you are counting how many days you did a certain activity, you would use the word "jour." On the other hand, "journée" is used in contexts where the word "day" is not a measure word. If you are just "talking about your day" or describing the day itself, you would use "journée." https://www.quora.com/In-the-French-language-what-is-the-difference-between-jour-and-journ%C3%A9e-In-which-situations-are-each-of-them-used
The Duo computer accepts only the word order programmed into it. To make your more natural statement you had to add a word (it) that wasn't in the original.
Sometimes the word order has to be changed when translating to make a more sensible comment in the target language. Occasionally a word has to be added because of grammar considerations. But this is not one of those cases. The programmers did not include your preferred translation as an option.
Depends on what you mean by the word translate. Your sentence means the same thing but you changed the words and grammar in your translation. Not because the literal translation doesn't work in English but because you prefer to use different wording to express the same meaning.
That is ok but not if you are trying to show your ability to translate the actual words given to you.