Query Time Zones

The Query Time Zone options are Origin Time and UTC.

• Origin time is the local time in the operator’s time zone.

• UTC time is Greenwich Mean Time, also known as Coordinated Universal Time or Zulu.

If Use Specific Time is selected, you can select between the two query time zone options. If Use Specific Time is not selected, the selected Duration predefined time interval always queries for data using the UTC time zone.

To avoid problems during the Daylight Saving Time switch, we recommend that you always use UTC in Query Time Zone. If you use Local Time instead, it is possible that alarm records will be missing for the transition period from Daylight Saving Time to Normal Time.

If you are running several different computers with different time zone settings, and they are all logging to the same alarm database, each record will get the time stamps in UTC, plus the time zone offset and daylight saving adjustment needed to convert that time stamp to the corresponding Origin Time. As a result, every entry in the database has two time stamps: the UTC time and the Origin Time from the computer that did the logging. This makes retrievals faster. In the table entries, the UTC time is identified as the "Transition Time" and the Origin Time is identified as the "EventStamp."