TS ISO 8601-2

TS ISO 8601-2 extends the core date-and-time rules of ISO 8601-1 by defining additional representations for information interchange. It focuses on Gregorian-calendar dates and 24-hour clock times, but allows them to be expressed in more flexible forms when the information is incomplete, approximate, uncertain, or structured in a more complex way.

What the extensions add

The standard covers extended time intervals, divisions of a year, sets and choices of calendar dates, grouped time-scale units, repeat rules for recurring intervals, and date-and-time arithmetic. It is also applicable to times and time shifts based on Coordinated Universal Time (UTC). In practice, this means the standard supports not only a single timestamp, but also patterns, ranges, and calendar logic that commonly arise in data exchange and scheduling systems.

Technical context and boundaries

• The Gregorian calendar is the baseline calendar model used by the standard for date representation.
• The 24-hour clock provides an unambiguous way to express times within a day.
• Approximate, uncertain, or partially unspecified dates are useful when records are incomplete but still need a standardized representation.
• Non-Gregorian calendar elements and times not based on the 24-hour clock are excluded.
• The document does not address character encoding of the representations it defines; it specifies the character strings themselves.