Forewarning of date data GPS output

To JRC GPS users: Customers who utilize GPS date data from the GPS navigator, receiver and plotter, and also GPS receiver installed in the JRC JUE-75A Inmarsat-C models will experience difficulties on 17 August 2008 as the date data will output and display 1 January 1989.

The maximum possible duration of the date data from the GPS is 19.6 year. As a result, at 0:00AM (UTC), 17 August 2008, the date data will automatically relapse to the initial commencement date 1 January 1989.

The actual date will be incorrect. The time display and output will not be affected, and the positioning function will operate normally, though may temporarily be interrupted, taking a longer time or fail to fix the position after the date reverts.

Find below list of affected equipment and appropriate countermeasures per model. Contact our service agent or sales representative to arrange countermeasures. Due to age of GPS model concerned, costs for any modifications will be at the customer’s expense.


Equipment Objective models Counter measures
GPS navigators JLR-4200/6000 Retrofit to JLR-7700Mk2
  JLR-4110/6000Mk2 Replace with the GPS receiver converting kit or retrofit to JLR-7700Mk2
  JLR-4110Mk2/6800 Replace the receiver ROM and lithium battery or replace with the GPS receiver converting kit
  JLR-4500/4510 Retrofit to JLR-4340 and NWZ-4551
GPS receivers JLR-4300/4310 Retrofit to JLR-4340
  JLR-4400/5500 Out of objective
GPS plotters JLU-121/121P Add DGPS connection unit (NQA-1481DF) and retrofit to JLR-4340. Or, retrofit to JLZ-700 and JLR-4340
  JLU-128 Retrofit to JLR-4340
Inmarsat C model JUE-75A Replace internal GPS receiver with new GPS kit (6EZSC00031). Or, input GPS data to JUE-75A from external GPS e.g. JLR-7700Mk2


(!) All other JRC GPS and Inmarsat-C models do not require countermeasures.

If any of the above GPS equipment is used in combination with the following equipment, the functionality will be affected.

  • Electronic Chart Display and Information System (ECDIS)
  • Chart Radar
  • Ship Security Alert System (SSAS)
  • Simplified Voyage Data Recorder (S-VDR)
  • Other equipment employing the date data from a GPS

For more information, and countermeasures, please contact our service agents or sales representatives.