/// <inheritdoc />
public int GetWeekYear(LocalDate date)
{
YearMonthDay yearMonthDay = date.YearMonthDay;
YearMonthDayCalculator yearMonthDayCalculator = date.Calendar.YearMonthDayCalculator;
unchecked
{
// Let's guess that it's in the same week year as calendar year, and check that.
int calendarYear = yearMonthDay.Year;
int startOfWeekYear = GetWeekYearDaysSinceEpoch(yearMonthDayCalculator, calendarYear);
int daysSinceEpoch = yearMonthDayCalculator.GetDaysSinceEpoch(yearMonthDay);
if (daysSinceEpoch < startOfWeekYear)
{
// No, the week-year hadn't started yet. For example, we've been given January 1st 2011...
// and the first week of week-year 2011 starts on January 3rd 2011. Therefore the local instant
// must belong to the last week of the previous week-year.
return(calendarYear - 1);
}
// By now, we know it's either calendarYear or calendarYear + 1. Check using the number of
// weeks in the year. Note that this will fetch the start of the calendar year and the week year
// again, so could be optimized by copying some logic here - but only when we find we need to.
int weeksInWeekYear = GetWeeksInWeekYear(calendarYear, date.Calendar);
// We assume that even for the maximum year, we've got just about enough leeway to get to the
// start of the week year. (If not, we should adjust the maximum.)
int startOfNextWeekYear = startOfWeekYear + weeksInWeekYear * 7;
return(daysSinceEpoch < startOfNextWeekYear ? calendarYear : calendarYear + 1);
}
}
/// <inheritdoc />
public int GetWeekOfWeekYear(LocalDate date)
{
YearMonthDay yearMonthDay = date.YearMonthDay;
YearMonthDayCalculator yearMonthDayCalculator = date.Calendar.YearMonthDayCalculator;
// This is a bit inefficient, as we'll be converting forms several times. However, it's
// understandable... we might want to optimize in the future if it's reported as a bottleneck.
int weekYear = GetWeekYear(date);
int startOfWeekYear = GetWeekYearDaysSinceEpoch(yearMonthDayCalculator, weekYear);
int daysSinceEpoch = yearMonthDayCalculator.GetDaysSinceEpoch(yearMonthDay);
int zeroBasedDayOfWeekYear = daysSinceEpoch - startOfWeekYear;
int zeroBasedWeek = zeroBasedDayOfWeekYear / 7;
return(zeroBasedWeek + 1);
}
/// <inheritdoc />
public int GetWeekOfWeekYear(LocalDate date)
{
YearMonthDay yearMonthDay = date.YearMonthDay;
YearMonthDayCalculator yearMonthDayCalculator = date.Calendar.YearMonthDayCalculator;
// This is a bit inefficient, as we'll be converting forms several times. However, it's
// understandable... we might want to optimize in the future if it's reported as a bottleneck.
int weekYear = GetWeekYear(date);
// Even if this is before the *real* start of the week year due to the rule
// having short weeks, that doesn't change the week-of-week-year, as we've definitely
// got the right week-year to start with.
int startOfWeekYear = GetWeekYearDaysSinceEpoch(yearMonthDayCalculator, weekYear);
int daysSinceEpoch = yearMonthDayCalculator.GetDaysSinceEpoch(yearMonthDay);
int zeroBasedDayOfWeekYear = daysSinceEpoch - startOfWeekYear;
int zeroBasedWeek = zeroBasedDayOfWeekYear / 7;
return(zeroBasedWeek + 1);
}
internal int GetDayOfWeek([Trusted] YearMonthDay yearMonthDay) => GetDayOfWeek(yearMonthDayCalculator.GetDaysSinceEpoch(yearMonthDay));