Notes on use of GPS receivers or GPS network time servers

Some GPS receivers or GPS network time servers (NTP/SNTP servers) may not be able to synchronize the time correctly every approximately 19.6-year due to the “GPS Week Number Rollover” issue (*1).
Next time, this issue will occur at 11:59:42 (p.m.) on April 6, 2019 of the Coordinated Universal Time (UTC).
*1: Further detailed information is at: <https://www.gps.gov/>

Please contact the supplier of the GPS receiver or the GPS network time server to confirm whether the model is affected by the “GPS Week Number Rollover” issue or not.
If the model is the type which is affected by the “GPS Week Number Rollover” issue, please confirm when the internal counter is reset to zero and what the counter measure against this issue is. Based on the information from the supplier, execute the measure as soon as possible before the issue happens mentioned.