Time Zones

Time zones are defined relative to Coordinated Universal Time (UTC), the primary time standard by which clocks and time are regulated. For example, Greenwich Mean Time is UTC+0, Central European Time is UTC+01:00 (one hour ahead of UTC), and Eastern Standard Time is UTC-05:00 (five hours behind UTC).

Geocortex Essentials provides settings that control how date/time data is interpreted and displayed in HTML5 viewers:

Contexts where Configured Time Zones Apply

The Data Time Zone and Display Time Zone apply in the following contexts:

Daylight Saving Time

Some regions use Daylight Saving Time during the summer. Daylight Saving Time is offset from UTC by an additional hour. For example, during the summer London uses British Summer Time, which is UTC+01:00.

Browsers use JavaScript to calculate Daylight Saving Time. JavaScript assumes that the current year's Daylight Saving Time dates apply to every year, including years before Daylight Saving Time was first introduced. For example, if Daylight Saving Time is in effect in a particular region from March 13 to November 6 this year, then JavaScript outputs all date/time data between March 13 and November 6 in Daylight Saving Time. This can result in a misrepresentation of date/time data.

Specify the Time Zone that Date/Time Data is Stored In

This section describes how to configure the time zone for date/time data in feature attributes and ArcGIS tables. For information on configuring the time zone for data links, see Specify the Time Zone that a Data Link's Data is Stored In.

Date/time data in geographic information systems is conventionally stored in UTC. This allows the data to be stored without time zone information. For example, before storing the value June 12, 2010 6:00 PM Pacific Standard Time, which is UTC-08:00, conventionally you would convert it to UTC by adding eight hours to the value, which makes it June 13, 2010 2:00 AM. Applications that use the data can then assume that the data is in UTC and convert it to other time zones as needed.

If you have date/time data that is not stored in UTC, you can specify the data’s time zone in Manager using the Data Time Zone setting. This provides the information needed to adjust the values and display them correctly to users. Configuring the time zone does not affect the underlying data.

If your date/time data is not in UTC and you do not configure the Data Time Zone, the data may display incorrectly in viewers.

In ArcGIS Server 10.4 or newer, including ArcGIS Enterprise 10.5, ArcGIS services have a time zone setting for date fields. If you have set the time zone for an ArcGIS service, ensure the Data Time Zone in Essentials is UTC. If you set the time zone in both places, the data will display incorrectly in viewers.

You do not need to configure the Data Time Zone for ArcGIS time-aware layers. Time-aware layers have their own time zone setting in ArcGIS Server. Essentials and HTML5 viewers use the ArcGIS Server time zone setting instead of the Essentials time zone setting when displaying date/time data from time-aware layers.

Data Sources that the Data Time Zone Applies To

The Data Time Zone applies to:

The configured time zone does not apply to:

Configure the Data Time Zone

You can configure your data's time zone at the site level, the map service level, and the layer level. By default, the time zone is set to Default, which inherits the time zone from a higher level—layers inherit the time zone from the map service, and map services inherit the time zone from the site. If you leave a layer, the layer's map service, and the site all set to Default, UTC is assumed.

You can override inherited values by configuring a time zone at a lower level. For example, you could set a time zone for the site, but override it for a particular map service in the site, and override it again for a particular layer in the map service.

If your date/time data is stored in UTC, you do not need to configure the Data Time Zone.

To save yourself from doing more configuration than necessary, configure the time zone by starting at the site level and working down:

  1. Configure the site to use the time zone that most date/time data is stored in.

  2. Configure the time zone for map services that store their data in a different time zone than the site.

    A map service's time zone overrides the site's time zone.

  3. Configure the time zone for layers that store their data in a different time zone than the map service.

    A layer's time zone overrides the map service's time zone.

To specify the time zone that date/time data is stored in:

  1. Follow the instructions that apply to you:

    Configure the Site-Level Time Zone

    1. In Manager, edit the site that you want to configure, and then click Site Info in the side panel.

    Configure the Map Service-Level Time Zone

    1. In Manager, edit the map service that you want to configure, and then click the Display Settings tab.

      The Data Time Zone setting is in the Field Formatting area.

    Configure the Layer-Level Time Zone

    1. In Manager, click Map in the side panel, click the Map Services tab, expand the map service that the layer belongs to, and then click the Edit icon next to the layer.

    2. Click the Fields tab.

      The Data Time Zone setting is in the Default Formatting area.

  2. In the Data Time Zone drop-down list, select the time zone that the data is stored in.

    Alternatively, you can select a city that is in the same time zone as the stored data.

  3. Apply your changes.

Specify a Time Zone to Display Date/Time Data

By default, viewers display date/time data in the user's local time, which is determined from the device's time zone setting. Displaying the data in local time makes it easier for the user to work with the data in some situations.

For example, suppose that you host an application that shows the current location of trains in a rail network. The rail network crosses the continent, so individual date/time values may be in different time zones. Users see the all the values in their local time, without having to convert them, which makes travel planning easier.

In other situations, you may want your HTML5 viewers to always display date/time data in a particular time zone, instead of adjusting the displayed data to the end user's time zone.

For example, an organization with offices across the continental US may want date/time data to display in the time zone of the head office, no matter where the user is located. In this case, you can specify the Display Time Zone setting in Manager. When the Display Time Zone setting is configured, viewers do not adjust date/time data to the end user's time zone before displaying it. Instead, viewers adjust date/time data to the time zone specified in the Display Time Zone setting.

Data Sources that the Display Time Zone Applies To

The Display Time Zone applies to:

Configure the Display Time Zone

To specify the time zone to use to display date/time data:

  1. In Manager, edit the site that you want to configure, and then click Site Info in the side panel.

  2. In the Display Time Zone drop-down list, select the time zone that you want all date/time data to be displayed in.

  3. Click Apply Details.

Specify Time Zones in Reports

By default, report templates that use date/time data output the source database's raw date/time data. However, you can configure report templates to display date/time data columns with either the time zone of the machine running Essentials or the configured Display Time Zone setting.

While editing a report template in Geocortex Report Designer, locate the date/time field that you want to configure and edit its DataField.

For example, if your report template looks for date/time data from a field with the name MyDate, you can set the report DataField name to MyDate_ServTZ to use your Essentials server's time zone or to MyDate_DispTZ to use the configured Display Time Zone.

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Documentation Version 4.11