Setsuna (刹那 - Moment)

We usually use "second," "minute" and "hour" as units of time, and this fact is worldwide.

Apart from such general units in the world, Japanese people sometimes use "setsuna" (刹那) when expressing just a moment.

"Setsuna" is one of the concepts of time in Buddhism, and it refers to an extremely short time.

There are several detailed definitions -- one of most famous definitions is that the moment of flicking your fingers is equal to 65 setsuna.

Also, in countries that use the Chinese writing system, setsuna is used as a numerical unit that represents 10 to the power of -18.

刹那

我々が最も使う時間の単位は、秒、分、時などであり、これは世界共通です。

このような世界で一般的な単位とは別に、日本ではほんの一瞬を表現する際に「刹那」を使うことがあります。

「刹那」は仏教における時間の概念の一つで、極めて短い時間を表します。

定義は諸説ありますが、指をひとはじきする間に65刹那あるなどと言われています。

また、漢字文化圏では、10^-18という数の単位としても用いられています（実際に使われるケースはほとんどありません）。

What a wonderful word!

• We usually use "second," "minute" and "hour" as units of time, and this fact is worldwide.
• We usually use "second," "minute", and "hour" as units of time, and these units are used throughout the world.

  The comma is called the "Oxford comma". In this sentence, there is less chance of misunderstanding, but leaving it out can cause confusing sometimes.

• Apart from such general units in the world, Japanese people sometimes use "setsuna" (刹那) when expressing just a moment.
• Apart from such widely-used units in the world, Japanese people sometimes use "setsuna" (刹那) when expressing just a moment.

• "Setsuna" is one of the concepts of time in Buddhism, and it refers to an extremely short time.
• "Setsuna" is one of the concepts of time in Buddhism, and it refers to an extremely short (period of) time.

  optional

• There are several detailed definitions -- one of most famous definitions is that the moment of flicking your fingers is equal to 65 setsuna.
• There are several detailed definitions -- one of most famous definitions is that the time it takes to snap your fingers is equal to 65 setsuna.

  I'm not sure I understand 指をひとはじき, so this could be wrong.

• Also, in countries that use the Chinese writing system, setsuna is used as a numerical unit that represents 10 to the power of -18.
• Also, in countries that use the Chinese writing system, setsuna is used as a numerical unit that represents 10 to the -18th power.

Very interesting. Thanks for the post!