You may encounter a situation where ezAudit displays the "real time" of audit report items incorrectly. Most often, you'll see that the audit report data starts at a time that doesn't seem reasonable - either an hour behind or perhaps a couple of hours ahead what you think the correct time should be.
This generally occurs because of the way that an XStudio, DCS or Maestro system stores the actual time of an event in the audit data file and the likelihood that you mismatched the station configuration information to the DCS or Maestro system's actual storage method.
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Starting in the spring of 2007, daylight saving time (DST) start and end dates for the United States transitioned to comply with the Energy Policy Act of 2005. There have also been other related DST changes, time zone behavior, and settings for other parts of the world. Canada, for instance, also had significant changes. These changes can have a dramatic impact on the accuracy of audit data report times. See the topic on Time Zone Information for clarification on how you might be affected. |
How Audit Data Time Values are Stored
In short, an XStudio, DCS or Maestro system stores the actual event time (also called real time) in reference to GMT (Greenwich Mean Time), offset by the on-air system's time zone settings. It boils down to what time zone a given XStudio, DCS or Maestro unit "thinks" it's in, not necessarily the real time zone the system is operating within.
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The GMT (Greenwich Mean Time) time reference is now more popularly known as UTC (Universal Time Code). For purposes of this document, they mean one and the same thing. |
As an example, a DCS unit running with no time zone settings applied (via the AUTOEXEC.BAT file) "thinks" it's in the Pacific Time Zone (US) as a default. This means that if a spot (cart) plays at noon on, say, 9/21/2007, the event time is written to the audit file as an adjusted value of 7pm, 9/21/2007. This is because the time is adjusted forward 7 hours, the difference between PST & GMT (8 hours) minus 1 hour because the date, 9/21/2007, falls within Daylight Savings Time for the Pacific Time Zone. If your DCS unit is actually located in, say, the Central Time Zone (US), the audit report's actual or real time will display as 2pm, 2 hours "off" what it should be. The two-hour difference is the difference between the Central Time Zone (US) and Pacific Time Zone (US).
If your DCS unit is located in a time zone much further away from the Pacific Time Zone used in the example, the number of hours the report seems to be "off" can get very large.
With XStudio and Maestro systems, the basic time zone information is most often closer to "correct". As Maestro runs on the NT family of operating systems, most units will have had their time settings adjusted for the appropriate time zone in which the machine is located. However, Maestro documentation generally recommends that DST not be observed - that the machine's time zone settings be changed by un-checking (de-selecting) the "Automatically Adjust Clock for Daylight Saving Changes" checkbox in the operating system's Date/Time Properties dialog. In this scenario, you may find audit report information that's right during the non-daylight savings dates of the year, but "off" an hour during those dates that fall within daylight savings time.
How Does ezAudit Handle Report Times?
ezAudit is intended to provide the ability to report audit data's actual (or real) times without regard to the host PC's settings (that is, the machine on which you're running ezAudit). In order for the times to display correctly, though, you must set a given station's time zone settings, both the time zone and observe DST items, correctly. In addition, for complete accuracy, your host PC needs to have all current and historical time zone information in its registry - see the topic on Time Zone Information for additional details.
Nothing ezAudit does with audit data is destructive, so if you need to experiment with time zone settings, go ahead. Load an audit file for the station who's times seem to be "off". Then, open the Preferences | Stations tab and change the station's time zone or observe DST settings, preferably one at a time. Apply the changes and close the Preferences dialog. The data's times will be updated to reflect your new time zone settings.
