変則

1. Origins, structure, and basic meaning

• Structure: 変則 (へんそく) is a nominal stem describing a schedule or arrangement that departs from the regular pattern.
• Basic usage: 変則勤務の予定 modifies a work schedule altered for this week, while 変則的な組み合わせ describes pairings changed because participant numbers are low.

2. Common pitfalls and similar expressions

• Temporary schedule and irregular pairing
  • 変則勤務 differs from the normal work pattern, whereas 変則的な組み合わせ is an exception in composition. Irregularity does not automatically mean a rule violation or illegality.