24-hour clock

English

Noun

24-hour clock (plural 24-hour clocks)

1. A timekeeping convention in which the 24 hours of the day are each treated as a single period, rather than two sets of 12 hours.
   • 1961 December, “Talking of Trains: 24hr clock experiment at York”, in Trains Illustrated, page 712:

     Train and steamer services to and from the Continent, including the boat trains in England, have long had 24hr clock indications, mainly to conform with the practice of connecting Continental railways, for Irish services are exempt.

Synonyms

• military time (chiefly US)
• continental time (chiefly UK)

Antonyms

• 12-hour clock

References

• “24-hour clock”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.