Iso 8601 date format => http://ertipurpders.nnmcloud.ru/d?s=YToyOntzOjc6InJlZmVyZXIiO3M6MjE6Imh0dHA6Ly9iaXRiaW4uaXQyX2RsLyI7czozOiJrZXkiO3M6MjA6IklzbyA4NjAxIGRhdGUgZm9ybWF0Ijt9 On an individual level this uncertainty can be very frustrating, in a business context it can be very expensive. Thank you for the clarification. An interval is a lone duration, a duration then solidus then a time point, a time point then solidus then duration, or two time points separated by a solidus. Year -1 is the year preceding year 0 a. This suggests to me that the parties must agree in advance as to whether date or time or both are being exchanged - thus there is no ambiguity because we are required to agree in advance whether we are writing a date or a time. The standard states that every date must be consecutive, so usage of the would be contrary to the standard because at the switchover date, the dates would not be consecutive. I cannot continue a discussion with a person who adopts such tactics. I didn't do it very elegantly, I'll never be a great writer that's for sure. This content is no longer maintained. Combining that with the omission it reads as though it can only be used, in general, for Gregorian calendar dates. It explicitly excludes durations and dates before the. Obviously the Gregorian calendar was introduced when there were no good clocks; today we have the possibility of deciding when days begin and end by referring to atomic clocks, and ignoring the passage of the Sun across the sky, but that was not possible in the 16th century. Another aspect is that notes in the definitions section have a different set of rules and interpretation than notes within the text. Regards,-- 2008-02-01 20:24+04 It has a fundamental error of omission, which will be offensive to many. ISO 8601: the Right Format for Dates - In this the great divide is between the Europeans, who write day. This document is a submission to W3C from Reuters Limited. Please see regarding its disposition. Comments on this document should be sent to. To reduce the scope for error and the complexity of software, it is useful to restrict the supported formats to a small number. For example it defines Basic Format, without punctuation, and Extended Format, with punctuation, and it allows elements to be omitted. This profile avoids the problem by expressing the year as four digits in all cases. This profile may be adopted by standards which require an unambiguous representation of dates and times. As different standards have their own requirements regarding granularity and flexibility, this profile offers a number of options. iso 8601 date format An adopting standard must specify which of these options it permits. Formats Different standards may need different levels of granularity in the date and time, so this profile defines six levels. Standards that reference this profile should specify one or more of these granularities. If a given standard allows more than one granularity, it should specify the meaning of the dates and times with reduced precision, for example, the result of comparing two dates with different precisions. The formats are as follows. Exactly the components shown here must be present, with exactly this punctuation. A standard referencing this profile should permit one or both of these ways of handling time zone offsets.