Out of rush hours

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1906, originally in reference to electrical systems, from off (adv.) + peak (n.).

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
off-peak \off-peak\ adj. Having less than maximal use or demand or activity; -- of a period of time occurring as a defined part of a time cycle; as, off-peak telepone rates are available at night and on weekends; off-peak fares. [Narrower terms: off-season ...

WordNet Word definitions in WordNet
adj. of a period of less than maximal use or demand or activity; "off-peak telepone rates"; "off-peak fares" [ant: peak ]

Longman Dictionary of Contemporary English Word definitions in Longman Dictionary of Contemporary English
adjective EXAMPLES FROM OTHER ENTRIES ▪ At off-peak times senior citizens can use the sports centre at reduced rates. ▪ Take advantage of off-peak reductions for package holidays. ▪ Work on the highway will be done only during off-peak hours. EXAMPLES FROM ...

Wiktionary Word definitions in Wiktionary
a. During a period of less use or demand than the maximum (peak), generally overnight.