851.txt

* 定義

[FIG[
[FIGCAPTION[
[1] [SRC[[[ISO 8601:2004]] 2.1.6]]
]FIGCAPTION]
> non-negative quantity attributed to a time interval, the value of which is equal to the difference between the
time points of the final instant and the initial instant of the time interval, when the time points are quantitative
marks [SRC[IEC 60050-111]]
]FIG]