本文件规定了公历日期和基于24小时时钟的时间的其他表示形式，扩展了ISO 8601-1中定义的基本规则和复合元素。这些表示形式被指定为用于信息交换的字符串。它也适用于表示基于协调世界时（UTC）的时间和时间偏移。 这些扩展包括: -不确定或近似的日期，或未指定部分的日期； -延长时间间隔； -一年的划分； -设置和选择日历日期； -分组时间尺度单位； -重复周期性时间间隔的规则；和 -日期和时间算术。 本文件不包括非公历中的日期元素，也不包括24小时制中的时间。本文件不涉及本文件中指定的表示的字符编码。

This document specifies additional representations of dates of the Gregorian calendar and times based on the 24-hour clock that extend the basic rules and composite elements of those defined in ISO 8601-1. These representations are specified as character strings for use in information interchange. It is also applicable for representing times and time shifts based on Coordinated Universal Time (UTC). These extensions include: — uncertain or approximate dates, or dates with portions unspecified; — extended time intervals; — divisions of a year; — sets and choices of calendar dates; — grouped time scale units; — repeat rules for recurring time intervals; and — date and time arithmetic. This document excludes the representation of date elements from non-Gregorian calendars, or times not from the 24-hour clock. This document does not address character encoding of representations specified in this document.