TS ISO 8601-1

TS ISO 8601-1 defines the basic rules for representing Gregorian calendar dates and 24-hour clock times as character strings for information interchange, and it also covers composite representations of these elements together with UTC-based times and time shifts. It provides a common format so date-time information can be read and processed consistently across different systems.

Core concepts behind the representations

In general technical use, the ISO 8601 family is meant to make date and time notation predictable, machine-readable, and less ambiguous than local conventions. Gregorian dates, 24-hour clock times, and UTC-based time information are especially important in scheduling, recordkeeping, data exchange, and system integration. The underlying idea is to express components such as year, month, day, hour, minute, and, where needed, seconds in a structured order that can be interpreted consistently.

What this part includes and excludes

• Date representations based on the Gregorian calendar
• Time representations based on the 24-hour clock
• Combined date and time representations
• Representations of UTC-based times and time shifts
• Dates from non-Gregorian calendars and times not based on the 24-hour clock are excluded
• The document does not address character encoding for the representations it specifies

As a general interoperability standard, TS ISO 8601-1 is useful wherever date and time data must move between software, databases, documents, and communication interfaces without changing meaning. It standardizes how the information is written, while leaving character encoding outside its scope.