Issue
When using GPS local time to synchronize a meters clock, there are issues on a yearly rollover. The meters date erratically changes around midnight. If a meter is in a time zone that is GMT 5 hrs (eastern standard time), the meters clock may fluctuate between the GMT New Year roll over and the local time roll over five hours later. The date will then be incorrect.

Product Line
ION 7550, ION 7650, ION 7550 RTU, ION 8500, ION 8600

Environment
System time

Cause
The meters clock uses UTC. When the GPS outputs local time, some date manipulation is done on the incoming time before it is converted to UTC. The GPS does not output the year in its timestamps. The year of the meters clock can then be different than the year assumed by the GPS. This problem is exasperated when the New Year roll over is from a leap year to a non leap year.

Resolution
Planned resolution is upgrading firmware to V261 on the ION8XXX Meters, V360 on the ION7X50 Meters, and V220 on ION7550 RTU meters. A workaround is to set the GPS and the meter to use UTC time synchronization.