This is usually equal to the normal Gregorian year (as returned by
glib.date_time.DateTime.getYear), except as detailed below:
For Thursday, the week-numbering year is always equal to the usual
calendar year. For other days, the number is such that every day
within a complete week (Monday to Sunday) is contained within the
same week-numbering year.
For Monday, Tuesday and Wednesday occurring near the end of the year,
this may mean that the week-numbering year is one greater than the
calendar year (so that these days have the same week-numbering year
as the Thursday occurring early in the next year).
For Friday, Saturday and Sunday occurring near the start of the year,
this may mean that the week-numbering year is one less than the
calendar year (so that these days have the same week-numbering year
as the Thursday occurring late in the previous year).
An equivalent description is that the week-numbering year is equal to
the calendar year containing the majority of the days in the current
week (Monday to Sunday).
Note that January 1 0001 in the proleptic Gregorian calendar is a
Monday, so this function never returns 0.
Returns the ISO 8601 week-numbering year in which the week containing datetime falls.
This function, taken together with glib.date_time.DateTime.getWeekOfYear and glib.date_time.DateTime.getDayOfWeek can be used to determine the full ISO week date on which datetime falls.
This is usually equal to the normal Gregorian year (as returned by glib.date_time.DateTime.getYear), except as detailed below:
For Thursday, the week-numbering year is always equal to the usual calendar year. For other days, the number is such that every day within a complete week (Monday to Sunday) is contained within the same week-numbering year.
For Monday, Tuesday and Wednesday occurring near the end of the year, this may mean that the week-numbering year is one greater than the calendar year (so that these days have the same week-numbering year as the Thursday occurring early in the next year).
For Friday, Saturday and Sunday occurring near the start of the year, this may mean that the week-numbering year is one less than the calendar year (so that these days have the same week-numbering year as the Thursday occurring late in the previous year).
An equivalent description is that the week-numbering year is equal to the calendar year containing the majority of the days in the current week (Monday to Sunday).
Note that January 1 0001 in the proleptic Gregorian calendar is a Monday, so this function never returns 0.