Definition
Week number according to the ISO-8601 standard, weeks starting on Monday.
Representation
| Data Type | DATE |
|---|---|
| Format | NN |
| Maximum character length | 2 |
Comments
ISO week-numbering year (also called ISO year informally) has 52 or 53 full weeks.
The ISO 8601 definition for week 01 is the week with the first Thursday of the Gregorian year (i.e. of January) in it. The following definitions based on properties of this week are mutually equivalent, since the ISO week starts with Monday:
- It is the first week with a majority (4 or more) of its days in January.
- Its first day is the Monday nearest to 1 January.
- It has 4 January in it. Hence the earliest possible first week extends from Monday 29 December (previous Gregorian year) to Sunday 4 January, the latest possible first week extends from Monday 4 January to Sunday 10 January.
- It has the year's first working day in it, if Saturdays, Sundays and 1 January are not working days.
If 1 January is on a Monday, Tuesday, Wednesday or Thursday, it is in W01. If it is on a Friday, it is part of W53 of the previous year. If it is on a Saturday, it is part of the last week of the previous year which is numbered W52 in a common year and W53 in a leap year. If it is on a Sunday, it is part of W52 of the previous year.
References
ISO 8601
Related content
| Relation | Count |
|---|---|
| Data Elements implementing this Value Domain | 1 |