'post-hours' originates from the combination of 'post-' meaning 'after' and 'hours' referring to a specific time period.

'post-hours' evolved from the concept of 'post' as a prefix meaning 'after' and 'hours' as a measure of time, forming a term used in modern English to describe activities occurring after regular working hours.

Initially, it meant 'after the designated time period,' and this meaning has largely remained the same in modern usage.