Hierarchy classification:

1. top of the aat hierarchies
2. Physical Attributes Facet
3. Attributes and Properties (hierarchy name)
4. [attributes and properties by specific type]
5. form attributes
6. size/dimensions
7. [size/dimensions by unit]
8. size/dimension units for duration
9. months
10. [months for Gregorian and Julian calendars]

Anotations

Scope note:

The fourth month of the year in the Julian and Gregorian calendars, containing 30 days and falling between March and May. Its name probably derives from the Latin aperire (“to open”), a possible reference to plant buds opening at this time of year in Rome.