day
The French word for day is "jour". It is used in a similar way to the English word, to refer to a period of 24 hours. For example, "Je vais à l'école tous les jours" means "I go to school every day".
He reads a book a day
This sentence is used to describe a daily habit or routine, in this case, the person reads one book per day. 'Par jour' means 'a day' or 'per day' in French.
Good day to all
This phrase is used when you want to greet a group of people, equivalent to 'Good day to all' in English. 'Bon jour' means 'Good day' in French.
Every day counts
This sentence is used to emphasize the importance of time, implying you should value every day. 'Chaque jour' means 'every day' in French.