GPS week number rollover

Important notice

GPS week number rollover

To JRC Global Positioning System (GPS) users: We would like to announce that GPS week number rollover is to occur on some of our GPS' on 17 August 2014.

The week number counter in GPS resets once every 1023 weeks, which is approximately 19.6 years. The week number counters for the GPS in the discontinued models below started their week count from the 1st January 1995. It is on the 17th August 2014 at 0:00 AM (UTC) that the week number counters rollover will occur. The subject models are designed not to turn the clock back 19.6 years, and will continue to work correctly under normal use.

However, please note that time and date will go back to the starting date above when a master-reset of equipment or a battery replacement is carried out. In this case, customers are required to configure the initial settings.


EquipmentModelsSerial numberInitial setting procedure
GPS navigator JLR-4110Mk21 Up to KC57185 JLR-4110Mk2
  JLR-68001 Up to KD40400 JLR-6800
  JLR-4110Mk2 KC57186 and later JLR-4110Mk2
  JLR-6800 KD40401 and later JLR-6800
  JLR-7700 All JLR-7700
GPS receiver JLR-4320/4321 All NWZ-4551/J-NAV500, NWU-800

Other GPS equipments are NOT subjected to this rollover in 2014. For more information, and countermeasures, please contact our service agents or sales representatives.

  1. If the GPS receiver converting kit was attached for the rollover in 2008, next rollover will be 8th September 2024.