Calendar Description
The ISO Week calendar scheme is a system of numbering the weeks of the year and is based on the Gregorian calendar. A week is defined as Monday being day 1 through to Sunday day 7. The first week of the year is defined as the week containing the first Thursday of the Gregorian year. The ISO Week year thus has 52 or 53 weeks (364 or 371 days). The ISO Week year does not quite match the Gregorian year, with the year change occurring on the 29th, 30th or 31st of December, or the 1st, 2nd, 3rd or 4th of January - whichever day Monday falls.
Use Case
Details of the scheme were published in 1976 by the International Standards Organisation in their ISO 2015:1976 document. This was superseded in 2004 by the ISO 8601:2004 and later publications.
Definition
| Record | ||
|---|---|---|
| year | week | wday |
The ISO Week calendar is defined in terms of the Gregorian calendar.
The week is as defined for the wday field in the
Seven Day Week page.
The first week of the year is defined as the week containing the first Thursday
of the Gregorian year.
The Record consists of three Fields named year,
week, and wday.
| isow | year | week | wday |
|---|---|---|---|
| 1 | 1 | 1 |
| g | year | month | day |
|---|---|---|---|
| 1 | 1 | 1 |
| jdn | day |
|---|---|
| 1721426 |
Script
| Default Script |
|---|
| grammar isow { lexicons w; alias field { Day, wday; Week, week; Year, year; } alias pseudo { d, Day; ww, Week; yyyy, Year; } alias unit { d, day; y, year; w, week; } format ywd { rules iso8601 week; } format hc_ywd, "(Year)| (Week)| (Day:w:a)"; format "hc_ywd+", "(Year)| (Week)| (Day:w)"; format hc_iso, "(Year)| (Week)| (Day)"; pref ywd; } scheme isow { name "ISO:8601 Standard Week"; base isoweek; grammar isow; } |
| example/iso5.hcs Script |
|---|
| format isow:y5wd { rules iso8601 week year5; } |
| example/iso6.hcs Script |
|---|
| format isow:y6wd { rules iso8601 week year6; } |
