“Let’s call it a day!”の意味は？

BBCのコメディ『Only Fools And Horses』を題材にして、ETC英会話のコリン先生のレッスンを受けています。

デルが企画したロンドンのバスツアーには、結局、一晩待っても誰一人お客さんが来ませんでした。

今回の失敗にもめげずに、億万長者になる夢を語るデルですが、ロドニーに茶々を入れら、さすがに肩を落とします。そんな時に、デルが言った一言です。

Come on, let’s call it a day.

Let’s finish. who we say, call it a day mean they’ve been working from 8 o’clock. 6 o’clock now. You have not finished the work. But everybody is tired. So tomorrow is another day. Let’s call it a day. It only means it, doesn’t mean you finished, but just mean we had enough. That is enough for one day. Let’s call it a day. Enough is enough. We are tired. It is very hot. Tomorrow is another day.

– So still nothing finished, but…

Yeah, it’s very common use, though. It’s very, very common. Let’s finish! Let’s stop! What you are saying is “you had enough? “yeah, I am tired” “me, too” “let’s finish! Tomorrow is another day.” But it doesn’t mean, “For thank goodness. we’ve finished. now we can go home.” You wouldn’t say “let’s call it a day”. “Call it a day” is something that is continuing on, not finished yet.

■出演
・ETC英会話のコリン先生

■聞き手
・青樹洋文

◆使用楽曲 (BGM)
“Toxic Rainfall” of some1else from ccMixter