Rationale
Age is a key variable for determining the demographic characteristics of a population.
Classification of age/date of birth
Age is a flat classification with single–year categories from 0 years to 119 years inclusive, plus a category for 120 years and over.
Date of birth is derived from three flat classifications; date of birth day, date of birth month and date of birth year. Day has single categories 01 to 31 (representing the days of the month). Month has single categories 01 to 12 (representing the months of the year). Year has single categories (representing 120 years back from the current year). For example the 2007 code structure for the year classification ranges from 1887 to 2007. All three classifications also have residual categories which are defined in Glossary and references.
Age
| Classification |
Age – New Zealand Standard Classification |
| Abbreviation |
AGE |
| Version |
V1.0 |
| Effective date |
26/01/1995 |
Date of birth – day
| Classification |
Date of Birth – Day Classification |
| Abbreviation |
BIRTHDAY |
| Version |
V1.0 |
| Effective date |
30/03/1999 |
Date of birth – month
| Classification |
Date of Birth – Month Classification |
| Abbreviation |
BIRTHMON |
| Version |
V2.0 |
| Effective date |
30/03/1999 |
Date of birth – year
| Classification |
Date of Birth – Year Classification |
| Abbreviation |
BIRTHYR |
| Version |
V12.0 |
| Effective date |
01/01/2007 |