---
title: "Upstream Last Updated"
canonical: "https://wiki.patientsknowbest.com/space/api/3711959069/Upstream%20Last%20Updated"
format: markdown
---
[http://fhir.patientsknowbest.com/structuredefinition/upstream-last-updated](http://fhir.patientsknowbest.com/structuredefinition/upstream-last-updated)

[https://www.hl7.org/fhir/STU3/structuredefinition.html](https://www.hl7.org/fhir/STU3/structuredefinition.html)

## description

Aggregated resources are modified versions of upstream resources (e.g. FHIR resources provide directly to a Customer box).

As such, the lastUpdated timestamp of the aggregated resource might be more recent than that of the upstream resource, and hence less meaningful for some use cases.

This extension is generated by PKB to help with that problem, and it tracks in priority order: 

- the value of the upstream [http://fhir.patientsknowbest.com/structuredefinition/recorded-date](http://fhir.patientsknowbest.com/structuredefinition/recorded-date) extension (if available)
- or else: the meta.lastUpdated value of the upstream resource

## context

This extension is only populated on the Appointment resource.

## type

Extension

## element type

dateTime