おに の いぬま に せんたく

The Japanese proverb "While the demon is away, do the laundry", which translates as "While the demon is away, do the laundry", does not actually refer to the presence of demons or devils, but to doing something when others are not paying attention. It suggests acting on an opportunity or getting things done under the watchful eye of others.

In English, expressions with similar meanings include "While the cat's away, the mice will play", "Make hay while the sun shines." and "Strike while the iron is hot." These expressions emphasise making the most of a particular situation or opportunity.

For example, imagine a group of students planning a surprise party for their teacher while the teacher is out of town for a conference. They might use the opportunity of the teacher's absence to decorate the classroom and organize the party preparations. In this scenario, they are metaphorically "doing the laundry while the demon is away," taking advantage of the moment when their teacher's attention is elsewhere to carry out their plans.

Similarly, in a business context, employees might take advantage of a period of low workload when the boss is out of the office to catch up on tasks or initiate new projects. This aligns with the idea of "making hay while the sun shines," seizing the opportunity to be productive while conditions are favorable.

Overall, "鬼の居ぬ間に洗濯 （おに の いぬま に せんたく）" and its English equivalents convey the importance of seizing opportunities and taking action when circumstances are favorable, even if it means acting when others are not paying attention. It emphasizes the value of initiative and resourcefulness in making the most of any situation.