---
title: "Temporal Class"
slug: "glossary-temporal-class"
updated: 2023-02-02T15:37:46Z
published: 2023-02-02T15:37:46Z
canonical: "docs.ursahealth.com/glossary-temporal-class"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ursahealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Temporal Class

Time plays a crucial role in many data analytic exercises, especially in health care. A patient disease status changes over time, a certain event should happen within some span of time relative to another event, a period of membership must be some minimum length before the patient is qualified to be included in a program, etc.

Consequently, there are a lot of features in Ursa Studio to implement logic related to time. One foundational concept is an object's *Temporal Class*. That is, whether the object should be treated as an *Entity*, *Event*, or *Interval*.

## Temporal Class: Entity

A temporal class category denoting that an object’s observations do not represent a moment in time or a period of time. Rather, these objects, for analytical purposes, are considered to have a continuous presence. For example, an object capturing information about a patient would have an entity temporal class.

## Temporal Class: Event

A temporal class category denoting that an object’s observations represent a moment in time. For example, an object capturing information about clinician office visits would generally have an event temporal class.

## Temporal Class: Interval

A temporal class category denoting that an object’s observations represent a period of time with a start and end date. For example, an object capturing information about a home health episode of care that starts on a date and ends 60 days later would have an interval temporal class.

Interval objects will allow users to signal if the object is a timeline or not. Records in a timeline object are intervals that must be non-overlapping within an entity, such as a patient.