夜や分ぶん遅おそく

adverb, noun

late at night; at a late hour

Polite or formal expression for late-night timing, often used in business or customer-service contexts.

• 夜や分ぶん遅おそくに申もうし訳わけございません。

  I apologize for calling at this late hour.

• 夜や分ぶん遅おそくまでお仕し事ごとお疲つかれさまです。

  Thank you for your hard work until late at night.