Very few states have multiple time zones, but in this event, it is helpful to know the exact time handling in AirVision.

In the Site/Parameter table, the "System" is defined as having a time zone (for the central PC), and each site may have its own time zone as well. The time zone difference is used to calculate appropriate polling times, but all data is stored in the database and reported as local time for the site (e.g., data is not adjusted to central time). This is the same behavior used in the E-DAS Ambient product.

The only exception to this handling is the Automatic Data Validation Processor (ADVP), when confronted with cross-site comparisons. Because the time comparisons are assumed to be 'same time', the time zone delta is used when drawing data from the database for comparison (e.g., comparing 1pm data in Central zone with 2pm data in Eastern zone).


If the time zone is ever incorrectly set, it is recommended that the AirVision Service be restarted after saving the time zone change for proper polling to resume. Even so, the polling status table may take an hour to 'catch up' and resume polling, especially if setting the System time zone backward.