GPS Week Rollover

Released: April 8, 2019

Dear Customer,

Due to the recent “GPS week roll-over” that occurred on April 6th 2019 certain Beam Communications products have been impacted.  If you are using any of the products on the list but not using the GPS tracking feature, you are not affected.  However, if you are using the GPS tracking feature, the GPS tracking fix date and time may be wrong. The positioning performance is not affected.

An example of the Oceana 800 GPS tracking information with the wrong fix date and time sent on April 8, 2019.

Oceana800_Tracking, SQ4,TU-203837027,AL18,II353032040429082,LT-38.92037,LG149.14900,VL0,HT73,DR0,FU-203837027,


  • TU – the GPS date and time on an instance when the tracking information was requested.
  • FU – the GPS date and time from the most recent GPS fix. FU may either be equivalent or behind the TU time.

When the UNIX Date and Time code is converted to human readable date and time, the GPS date and time is wrong.

  • GMT: Wednesday, July 17, 1963 6:36:13 PM
  • Your time zone: Thursday, July 18, 1963 4:36:13 AM GMT+10:00
  • Relative: 56 years ago

The following Beam Communication products are affected:

  • 9555 PotsDOCK – Serial number PD510000 and earlier.
  • 9555 SatDOCK-G – Serial number SG505194 and earlier.
  • IsatDOCK Drive – Serial number MMN08809 and earlier.
  • IsatDOCK Marine – Serial number MMN09116 and earlier.
  • Oceana 800 – Serial number MFL03547 and earlier.

Important: The log file will show incorrect log date and time for these products.

Our team is working on a firmware update that will correct the GPS epoch roll-over on these products. The next communication on this issue will on May 3, 2019.


Beam Communications

Read More about the GPS Week Roll-Over

GPS is known to provide accurate positioning and timing information worldwide. When the GPS system first started to track time, the date and time was represented by a counter that could only count forward to a maximum of 1024 weeks, or approximately 19.7 years. After 1024 weeks, this counter “rolled over” to zero, and GPS time started counting forward again. The first rollover occurred in August of 1999. The second rollover occurred in April 6, 2019.