In search of lost/spare/wasted time

As the English Wikipedia article tells us, the first English translation of Marcel Proust's À la recherche du temps perdu bore the title Remembrance of Things Past, echoing Shakespeare's Sonnet 30, while later translations used the more literal In search of lost time. But Proust's original title also echoes two idiomatic phases in French, one of which is entirely missing in English, while the other one is weaker– and I've wondered for a while how intentional those echoes were.

For the first one, see Wiktionnaire's entry for "à temps perdu", with the gloss "En dehors de ses heures de travail rémunérées" ("Outside of paid working hours"). WordReference glosses "à temps perdu" as "in your spare time". For a real world example, see for example this Le Matin headline "L’infirmière vend du Harry Potter à temps perdu", which translates as "The nurse sells Harry Potter in her spare time".

And this is not a recent coinage — there are plenty of pre-Proust examples, for instance in this 1885 Histoire du socialisme.

These spare time/free time meanings are entirely missing from the English phrase "lost time".

For the second possible Proustian ambiguity, see Wiktionnaire's entry for the phrase "c'est du temps perdu", glossed as "Se dit en parlant des choses pour lesquelles on emploie inutilement du temps, de la peine, soit parce qu’elles ne le méritent pas, soit parce qu’elles ne doivent pas réussir" ("This is said when speaking of things for which one spends time and effort unnecessarily, either because they do not deserve it, or because they are not likely to succeed.").

The cited example is Jean-Paul Sartre's play Les main sales: "Ils veulent me faire parler, mais avec moi c’est du temps perdu", which translates as "They want to make me talk, but with me it's a waste of time".

More of the context (from here):

And a real-world headline: "Ces points de PIB qui s'envolent à cause du temps perdu à scroller sur les écrans" ("These GDP points that are disappearing because of the time wasted scrolling on screens"). Or this one: "Que de temps perdu sur nos téléphones !"  ("How much time we waste on our phones!").

There's a famous proverb from Poor Richard's Almanack that is consistent with this sense, "Lost time is never found again". And it's common to talk or write about certain ways to waste time as ways to "lose time", for example in the headline "Healthcare Organizations Are Stuck in Crisis Mode as Clinicians Lose Time to Administrative Work".

But whether the reasons are dull chores or pleasant diversions, I think that spending time and effort unnecessarily is more commonly expressed in English as waste/wasting/wasted time than lose/losing/lost time.