The meaning of potage du jour is the "soup of the day."
Du jour means "of the day".
la soupe (fem.), le potage (masc.), le velouté (masc.). "la soupe" is the vegetable one. "Le potage" and "le velouté" are nearly the same thing, but in a higher registry of language, or speaking of asparagus soup. You would use these (a bit showy) words on a restaurant menu.
Ton humeur du jour means 'your mood of the day' in French.
I believe you are asking about du jour, which means "of the day"
"Du jour" is a French term meaning "of the day." It is often used in menus to indicate a special dish or offering that is made fresh daily.
Soup du jour refers to liquid that has been cooked with meat, fish or vegetables, and contains pieces or chunks of those.
The soup du jour is chicken noodle!
Death du Jour was created in 1999.
Death du Jour has 436 pages.
Le Point du jour was created in 1949.
Du Jour menu is a French term reffering to daily specials. The phrase means of the day.
the plat du jour in French translates as todays' special. In a plat du jour menu, you have no change option (unless you pay more).