like 1/1/0), it has been suggested that the year 2000 is an excellent opportunity to change to the standard date notation.ISO 8601 is only specifying numeric notations and does not cover dates and times where words are used in the representation.Possible ISO week numbers are in the range 01 to 53. (There is one historic exception: the year in which the Gregorian calendar was introduced had less than 365 days and less than 52 weeks.) Proof: Per definition, the first week of a year is W01 and consequently days before week W01 belong to the previous year and so there is no week with lower numbers.Considering the highest possible week number, the worst case is a leap year like 1976 that starts with a Thursday, because this keeps the highest possible number of days of W01 in the previous year, i.e. In this case, the Sunday of W52 of the worst case year is day number 4 51*7=361 and 361-366=5 days of W53 belong still to this year, which guarantees that in the worst case year day 4 (Thursday) of W53 is not yet in the next year, so a week number 53 is possible.Note: The value 60 for ss might sometimes be needed during an inserted leap second in an atomic time scale like Coordinated Universal Time (UTC).
Advantages of the ISO 8601 standard date notation compared to other commonly used variants: As dates will look a little bit strange anyway starting with 2000-01-01 (e.g.
All of these alternatives can easily and automatically be distinguished from each other: The hyphens can be omitted if compactness of the representation is more important than human readability, for example as in In commercial and industrial applications (delivery times, production plans, etc.), especially in Europe, it is often required to refer to a week of a year.
Week 01 of a year is per definition the first week that has the Thursday in this year, which is equivalent to the week that contains the fourth day of January.
by Markus Kuhn International Standard ISO 8601 specifies numeric representations of date and time.
This standard notation helps to avoid confusion in international communication caused by the many different national notations and increases the portability of computer user interfaces.