'out-of-hours' originates from the English phrase 'out of hours,' where 'out' meant 'beyond' and 'hours' referred to 'working hours.'

'out of hours' was used in Middle English to denote times beyond the usual working hours and evolved into the modern term 'out-of-hours.'

Initially, it meant 'beyond the usual hours,' and this meaning has largely remained the same in modern usage.