# DV\_QUANTITY or DV\_DURATION?
**URL:** https://discourse.openehr.org/t/dv-quantity-or-dv-duration/15035
**Category:** Technical (archive)
**Created:** [17 December 2010 13:22 UTC](https://discourse.openehr.org/t/dv-quantity-or-dv-duration/15035 "2010-12-17T13:22:21Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Leonardo\_Moretti](https://discourse.openehr.org/u/Leonardo_Moretti)
#### Post date: [17 December 2010 13:22 UTC](https://discourse.openehr.org/t/dv-quantity-or-dv-duration/15035/1 "2010-12-17T13:22:21Z")
I'm wondering which is the correct use of DV\_DURATION and DV\_QUANTITY...
When using DV\_QUANTITY with property attribute 'time' (openehr::128) and
when using DV\_DURATION?
Regards
leo
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### Author:  [@thomas.beale](https://discourse.openehr.org/u/thomas.beale)
#### Post date: [17 December 2010 13:48 UTC](https://discourse.openehr.org/t/dv-quantity-or-dv-duration/15035/2 "2010-12-17T13:48:46Z")
The most usual uses are:
- DV\_DURATION - time periods in the ‘social’ timescale, e.g. hours, days, weeks, months, years - e.g. pregnancy, Expected Date of Delivery, duration of migraine
- DV\_QUANTITY - short time periods, being treated more mathematically, e.g. seconds or smaller, minutes and hours
both can be used for computation and can be inter-converted.
- thomas
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### Author:  [@ian.mcnicoll](https://discourse.openehr.org/u/ian.mcnicoll)
#### Post date: [17 December 2010 13:55 UTC](https://discourse.openehr.org/t/dv-quantity-or-dv-duration/15035/3 "2010-12-17T13:55:53Z")
Hi Thomas,
I think I have used DV+DURATION in all of these circumstances.. My
impression has been that DV\_QUANTITY with time property was
deprecated.
Ian
Dr Ian McNicoll
office / fax +44(0)1536 414994
mobile +44 (0)775 209 7859
skype ianmcnicoll
ian.mcnicoll@oceaninformatics.com
Clinical analyst, Ocean Informatics
openEHR Clinical Knowledge Editor www.openehr.org/knowledge
Honorary Senior Research Associate, CHIME, UCL
BCS Primary Health Care SG Group www.phcsg.org
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### Author:  [@system](https://discourse.openehr.org/u/system)
#### Post date: [23 December 2010 21:44 UTC](https://discourse.openehr.org/t/dv-quantity-or-dv-duration/15035/4 "2010-12-23T21:44:49Z")
Hi
The advantage of duration is that time can be expressed in the usual way 2
months, 6 weeks, 2hr 30min, 5min 30sec etc.
The Quantity has the advantage of being able to set a fixed unit. This is
necessary sometimes and although this can be done with duration it is not
really the focus. I think both have a role.
Cheers, Sam