noun
punctuality; on-time performance; reliability
Primarily used in the context of public transportation schedules, referring to how reliably services run on time. Can also refer to general reliability in timing.
日本の鉄道は定時性が高いことで知られている。
Japanese railways are known for their high punctuality.
このバス路線は定時性に問題がある。
This bus route has issues with on-time performance.
Means accuracy or correctness, not specifically about timing or schedules.
Compound of 定時 (fixed time, scheduled time) and 性 (-ness, property). The exact historical derivation is uncertain, but the term is a modern coinage used in transportation and logistics.