deĵori

Deĵori is a fossil, and it belongs to the same class as inspiri: the history is genuine, but the joint has fused and you cannot open it in Esperanto.

The French phrase is de jour, of the day. In a barracks or a hospital the officier de jour was whoever's turn it was that day, and the phrase attached itself to the idea of the rota - being the one who is on. Esperanto took the whole thing in as a single root, deĵor-, and there the trail stops. It looks as though it should divide, because de really is an Esperanto preposition and sits right there at the front, but ĵor is not a root, and a French preposition plus a French noun is not an Esperanto compound however French the pieces were when they set out.

What it means in use: to be on duty, to be the one on the rota, to be manning the post. Not the general "to work" - that is labori - and not "to serve" in the sense of serving somebody, which is servi. Deĵori is specifically about the shift.

The derivations are ordinary once you accept the root: deĵoro is a spell of duty or a shift, deĵoranto is the person currently on it, and deĵorejo the duty room. The same French jour is behind English journal, journey and sojourn, all of them measured out in days.