General Principles
- Date and time values are organized from the most to the least significant: year, month (or week), day, hour, minute, second, and fraction of second. The lexicographical order of the representation thus corresponds to chronological order, except for date representations involving negative years. This allows dates to be naturally sorted by, for example, file systems.
- Each date and time value has a fixed number of digits that must be padded with leading zeros.
- Representations can be done in one of two formats – a basic format with a minimal number of separators or an extended format with separators added to enhance human readability. The standard notes that "The basic format should be avoided in plain text." The separator used between date values (year, month, week, and day) is the hyphen, while the colon is used as the separator between time values (hours, minutes, and seconds). For example, the 6th day of the 1st month of the year 2009 may be written as "2009-01-06" in the extended format or simply as "20090106" in the basic format without ambiguity.
- For reduced precision, any number of values may be dropped from any of the date and time representations, but in the order from the least to the most significant. For example, "2004-05" is a valid ISO 8601 date, which indicates May (the fifth month) 2004. This format will never represent the 5th day of an unspecified month in 2004, nor will it represent a time-span extending from 2004 into 2005.
- If necessary for a particular application, the standard supports the addition of a decimal fraction to the smallest time value in the representation.
Read more about this topic: ISO 8601
Famous quotes containing the words general and/or principles:
“However energetically society in general may strive to make all the citizens equal and alike, the personal pride of each individual will always make him try to escape from the common level, and he will form some inequality somewhere to his own profit.”
—Alexis de Tocqueville (18051859)
“In child rearing it would unquestionably be easier if a child were to do something because we say so. The authoritarian method does expedite things, but it does not produce independent functioning. If a child has not mastered the underlying principles of human interactions and merely conforms out of coercion or conditioning, he has no tools to use, no resources to apply in the next situation that confronts him.”
—Elaine Heffner (20th century)