Definition of "off-peak"

off-peak

adjective
not comparable
1. During a period of less use or demand than the maximum (peak), generally overnight.
  Quotations
  At the time of writing some of the As are still running, and they are my favourite Underground cars. They are roomy and airy; the seats are transverse benches that you can stretch out and sleep on in the off-peak.
  2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 78
  What about overcrowding?Passengers are being asked to allow longer than normal for travel on some routes, due to reduced capacity on trains.If you can, you should travel at off-peak times. Employers are being asked to agree alternative or flexible working hours to support this.
  2020 May 20, “Social distancing: Questions and answers”, in RAIL, page 9
  As with other tourist lines, actual peak demand is from mid-morning to late afternoon - 'off peak' in conventional fares jargon. This can (and does) result in overcrowding at off-peak times and near empty trains at 'peak' hours. National one-size-fits-all simply does not apply on the S&C.
  2021 October 20, Mark Rand, “S&C: a line fit for tourists... and everyone?”, in RAIL, number 942, page 42