Duration - Dynamic NPU Manual



Time, time elapsed, age, life expectancy, time difference

Definition in words

A specific moment of time minus another specific moment of time

Note 1: Time is a SI base kind-of-quantity

Note 2: Component B may be a chemical, biological or physiological proces, e.g. coagulation

Definition by equation

Systematic terms

Duration of component B in system 1

Result type

Rational scale
  • Value sets are positive numerical values
  • Algebraic operations are allowed (a=nb; a≠nb)
Numerical values from 0-∞


s (second is the corresponding base measurement unit), h, d (day or 24 hours), m (month), year(s) etc.

Non-recommended term

Period of time


  1. Ferard G, Dybkaer R, Fuentes-Arderiu X. Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences : Recommendations 2016. 1 ed: Royal Society of Chemistry; 2016. 182 p. Doi:10.1039/9781782622451.
  2. IUPAC Goldbook homepage. http://goldbook.iupac.org
  3. BIPM homepage. https://www.bipm.org/en/bipm/tai/
  4. Lehmann HP, Fuentes-Arderiu X, Bertello L. Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996). Pure and Applied Chemistry. 2009;68(4):957-1000. doi:10.1351/pac199668040957.

Laboratory field


Clinical Chemistry


Example 1
Generic abbreviated
NPU10324 Pt—Urine sampling; duration = ? min
Full result NPU10324 Patient—Urine sampling; duration = 5 minutes
Abbreviated result NPU10324 Pt—Urine sampling; duration = 5 min
Written expression The duration of sampling of Mrs. Smith’s urine is [5] min.

Example 2
Generic abbreviated
NPU09355 Pt—Gestation period; duration = ? Week(s)
Full result NPU09355 Patient—Gestation period; duration = 11 Week(s)
Abbreviated result NPU09355 Pt—Gestation period; duration = 11 Week(s)
Written expression The duration of Mrs. Smith’s gestation period is [11] Week(s).

Reproduction and fertility

Example 3
Generic abbreviated
NPU10156 Pt—Amenorrhea; duration = ? Week(s)
Full result NPU10156 Patient—Amenorrhea; duration = 2 Week(s)
Abbreviated result NPU10156 Pt—Amenorrhea; duration = 2 Week(s)
Written expression The duration of Mrs. Smith’s Amenorrhea is [2] week(s).
Example 4
Generic abbreviated
NPU03411 Pt—Sexual abstinence; duration = ? d
Full result NPU03411 Patient—Sexual abstinence; duration = 20 days
Abbreviated result NPU03411 Pt—Sexual abstinence; duration = 20 d
Written expression The duration of Mr. Smith’s Sexual abstinence is [20] d.


NPU database, https://www.ifcc.org/ifcc-scientific-division/sd-committees/c-npu/npusearch/ and http://www.labterm.dk/default.aspx


  • Kind-of-property

    • Nominal kind-of-property

    • Kind-of-quantity

      • Unitary kind-of-quantity

        • Rational unitary kind-of-quantity

          • Duration


  • Dybkaer R. Concept system on ‘quantity’: formation and terminology. Accredit Qual Assur. 2013;18(3):253-60.
  • Dybkaer R. ISO terminological analysis of the VIM3 concepts ‘quantity’ and ‘kind-of-quantity’. Metrologia. 2010;47(3):127-34.
Date Term Note
1996-01-01 Duration Term established
Date Notes


2019-09-06 Other kinds-of-quantity with the same definition exist. Such as timelife spantime interval.