Time zone management
Whether your data was collected in a single time zone or many, it is important to understand how Tracking Analyst handles time zones.
Time zones for tracking layers
Time zones in Tracking Analyst are stored using the name of the time zone. For fixed-time tracking data, Tracking Analyst allows you to specify the time zone that your data was collected in when you add the tracking layer to your map. For real-time tracking layers, the time zone of the data is specified in the data stream. It is required that every tracking layer must have a time zone defined, and Tracking Analyst keeps track of the time zones for all tracking layers in a map. This is necessary to synchronize data that was recorded in different time zones. For example, if an event happened at 4:00 p.m. eastern time and a second event happened at 3:05 p.m. central time, Tracking Analyst will know that the first event happened before the second event.
Time zone for display
When working with tracking data, it is not enough to understand the time zone that was used to record your data. You must also understand the time zone that is used to display your data on the map. Tracking Analyst makes this simple by always using the local time zone of your computer when displaying data on the map. This means that the current time shown in Playback Manager and displayed on the map is always in the same time zone as your computer. For example, if your computer is in central time and Playback Manager is open and displaying 5:00 p.m., this means that the map is currently displaying 5:00 p.m. central time. If Playback Manager is closed, this means that Tracking Analyst is in real-time mode and the current time being displayed is the same as the current system time on your computer.
Daylight saving time
Adjusting for daylight saving can be confusing. When you specify the time zone for a tracking layer, you can also tell Tracking Analyst whether the data was collected using daylight saving time. This information is stored as a true or false value along with the time zone for each tracking layer. The display time always uses the daylight saving settings of your computer. If your computer is configured to adjust for daylight saving time, the display time will also adjust for daylight saving time.
The rules used to determine whether daylight saving is in effect (the beginning and ending dates for daylight saving) are taken from your operating system. This can be troublesome if the rules for daylight saving have changed in your area of the world. For example, if you are replaying data from several years ago and the rules for daylight saving have been changed since the data was collected, your data could be shifted by one hour when it is displayed on the map.