閏うるう秒びょう

noun

leap second

A one-second adjustment occasionally applied to Coordinated Universal Time (UTC) to keep it in sync with astronomical time.

• 今年ことしの6月がつ30日にちに閏うるう秒びょうが挿そう入にゅうされる予よ定ていです。

  A leap second is scheduled to be inserted on June 30th this year.