How Native American Reservations Are Represented in HERE Map Data and How Daylight Saving Time (DST) Is Applied

Applies To
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HERE Map Data (RDF and related datasets)
HERE location services and applications using administrative or cartographic features

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Summary
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Native American reservations in the United States are represented as cartographic polygon features in HERE map data. However, they are not part of the administrative area hierarchy. As a result, certain attributes—such as Daylight Saving Time (DST)—are not applied directly to reservations but are derived from surrounding administrative areas.

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Answer
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Native American reservations are modeled as cartographic features (polygons) rather than administrative regions.

Because of this:

They do not participate in administrative hierarchies
They do not carry administrative attributes such as DST directly

DST and other administrative properties are instead applied based on the relevant administrative area (e.g., state or country).

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Symptoms
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Customers may observe:

No administrative attributes associated with reservations
DST behavior that does not directly align with reservation boundaries
Difficulty determining whether a location falls within a reservation using standard administrative queries

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Root Cause
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### 1. Data Model Separation

HERE map data distinguishes between:

Administrative areas (e.g., country, state, city)
Cartographic features (e.g., reservations, polygons)

Native American reservations fall into the cartographic feature category, not administrative areas.

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### 2. Administrative Hierarchy Design

Administrative attributes such as:

Daylight Saving Time
Time zones
Governance boundaries

are applied only to official administrative levels.

Reservations are not included in this hierarchy.

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### 3. DST Assignment Logic

DST is applied:

First at the highest administrative level
Then cascades to lower levels if necessary

Since reservations are not part of this hierarchy, DST is not directly assigned to them.

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Impact
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| Scenario | Impact |
| --- | --- |
| Using administrative queries | Reservations are not returned |
| Applying DST logic | Uses surrounding administrative areas |
| Mapping reservation boundaries | Requires polygon-based logic |

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Recommended Actions
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### 1. Use Polygon-Based Logic

To identify whether a location falls within a reservation:

Perform spatial checks against reservation polygon data
Do not rely on administrative hierarchy queries

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### 2. Use Administrative Areas for DST

For DST and time-related calculations:

Use:
+ country
+ state
+ other administrative levels

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### 3. Combine Data Sources

For advanced use cases:

Combine:
+ administrative area data
+ cartographic polygon data

This ensures accurate geographic interpretation.

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Expected Behavior
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| Situation | Expected |
| --- | --- |
| Query by administrative area | Reservations not included |
| DST lookup at reservation level | Derived from admin area |
| Polygon-based map display | Reservation boundaries visible |

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Notes
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Native American reservations are represented as polygon features with unique identifiers in HERE map data
They are intentionally separate from administrative structures to avoid incorrect assumptions about governance or jurisdiction
DST rules follow administrative definitions and may not align exactly with reservation boundaries

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Related Information
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HERE Documentation: https://docs.here.com
HERE Developer Portal: https://platform.here.com/portal
HERE Support Portal: https://support.here.com

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Keywords
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HERE map data, Native American reservations, polygon features, administrative hierarchy, DST, daylight saving time, cartographic features, spatial data