Larger units are therefore always written before smaller units. It corresponds with the natural mathematic value of numbers. This sequence is known as “ descending notation”.
A duration that begins on Septemat 8:00 pm and lasts one month, five days, and three hours would be expressed per the ISO standard as follows: T20P1M5T3H.Īccording to the ISO standard, all values like times, dates or durations are shown in a certain order: They start with the largest unit and proceed to the next smaller value. In such cases, the start date or time is separated from the following duration by the letter “P”. What’s more, it’s not only used for time values but also for durations. The ISO 8601 standard is also known as ANSI INCITS 30-1997 (R2008) or NIST FIPS PUB 4-2 in the United States. This way, time and date information is standardized, resulting in fewer communication issues.
The representation of ISO date formats does away with the need for country-specific notations, at least in electronic formats. An ISO 8601 timestamp would therefore be: 12:07:22. Times are divided into hours, minutes, and seconds. According to the basic format of ISO 8601, the date “September 7, 2019” is written as follows: “20190907”, or when expressed with delimiters: “”. For greater clarity, they can also be separated by delimiters.
This basic format enables the numbers to be written directly after another. In the case of dates, the format is year-month-day. For times, they are expressed with the notation hours-minutes-seconds. The ISO 8601 standard defines an internationally recognized format for representing dates and times.