noun, noun which may take the genitive case particle 'no', adverb, adverb taking the 'to' particle
on the hour; exactly at the hour
Used to indicate that something happens exactly at the top of the hour, such as a clock striking or a scheduled event starting precisely at an hour mark. Often used in formal or scheduling contexts.
The clock struck the hour.
バスは正時に出発します。
The bus departs on the hour.
We bring you the news at the top of the hour.
every hour on the hour
Compound of 正 (しょう, 'correct' or 'exact') and 時 (じ, 'time' or 'hour'), literally meaning 'exact hour'.