# Dates and times in an Observation...

**Category:** [Technical (archive)](https://discourse.openehr.org/c/technical-archive/156)
**Created:** 2008-05-28 12:04 UTC
**Views:** 5
**Replies:** 2
**URL:** https://discourse.openehr.org/t/dates-and-times-in-an-observation/14750

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## Post #1 by @Bruno_Cadonna

Hi all,

I have a question regarding dates and times in openehr\.

I read the section "Time in the EHR" on page 29 of the document "The openEHR Reference Model \- EHR Information Model"\.

As far as I understood it, OBSERVATION\.data\.origin and OBSERVATION\.data\.event\[x\]\.time must not necessarily be within the interval COMPOSITION\.context\.start\_time and COMPOSITION\.context\.end\_time or after COMPOSITION\.context\.start\_time\.

Is this right?

An example:

A blood pressure measured by a patient on 2008\-01\-01 \(YYYY\-MM\-DD\) and reported to her physician on 2008\-01\-02 during an encounter, would have as COMPOSITION\.context\.start\_time the date 2008\-01\-02 and as OBSERVATION\.data\.origin as well as OBSERVATION\.data\.event\[x\]\.time the date 2008\-01\-01\.

For the sake of simplicity I omitted the time within the dates\.

Kind Regards
Bruno

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## Post #2 by @Thilo_Schuler1

Hi Bruno

> From my point of view your example is completely right\. The

composition context refers to the setting \(encounter etc\) when the
information was recorded, but the recorded information \(eg
observation\) could have happened before\.

Good to see you are still interested in openEHR\. If I remember
correctly, we quickly met in the Belgian Beer Cafe in Brisbane\. I am
currently at MIE in Goeborg and openEHR & archetypes have been
mentioned a lot\!

Cheers, Thilo

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## Post #3 by @thomas.beale

Bruno Cadonna wrote:
> Hi all,
>
> I have a question regarding dates and times in openehr\.
>
> I read the section "Time in the EHR" on page 29 of the document "The
> openEHR Reference Model \- EHR Information Model"\.
>
> As far as I understood it, OBSERVATION\.data\.origin and
> OBSERVATION\.data\.event\[x\]\.time must not necessarily be within the
> interval COMPOSITION\.context\.start\_time and
> COMPOSITION\.context\.end\_time or after COMPOSITION\.context\.start\_time\.
>
> Is this right?
>
> An example:
>
> A blood pressure measured by a patient on 2008\-01\-01 \(YYYY\-MM\-DD\) and
> reported to her physician on 2008\-01\-02 during an encounter, would
> have as COMPOSITION\.context\.start\_time the date 2008\-01\-02 and as
> OBSERVATION\.data\.origin as well as OBSERVATION\.data\.event\[x\]\.time the
> date 2008\-01\-01\.
>

\*This is correct\. The general reasoning is that the times in the
OBSERVATION history are the 'clinically relevant times' \- they are the
times the samples were taken from the patient\. WIth things like BP,
'sampling' and 'reading the result' occur pretty much together in time
and are often within the consultation \(but this doesn't have to be so,
as your example shows\), but for tissue and blood samples, swabs etc the
sample times could easily be at an earlier time than when the
result\-generating activity occurred \(e\.g\. you create a urine sample at
home and take it to the lab later on\), which is during the time of the
health service event\.

\- thomas beale

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**Canonical:** https://discourse.openehr.org/t/dates-and-times-in-an-observation/14750
**Original content:** https://discourse.openehr.org/t/dates-and-times-in-an-observation/14750