* 仕様書

[REFS[
- [2] [[ISO 8601:2004]] 2.1.17
]REFS]

* 定義

[FIG[
[FIGCAPTION[
[1] [SRC[[[ISO 8601:2004]] 2.1.17]]
]FIGCAPTION]
> series of consecutive [[time interval]]s of the same [[duration]] or [[nominal duration]]
]FIG]