/// <summary>
/// Create <see cref="DateInfo"/> by special year, month and offset info.<br />
/// 根据指定的年月和偏移信息创建 <see cref="DateInfo"/>
/// </summary>
/// <param name="year"></param>
/// <param name="month"></param>
/// <param name="weekAtMonth"></param>
/// <param name="dayOfWeek"></param>
/// <returns></returns>
public static DateInfo OffsetByWeek(int year, int month, int weekAtMonth, int dayOfWeek)
{
if (weekAtMonth == 0 || weekAtMonth > 5)
{
throw new ArgumentException("weekAtMonth is invalid.", nameof(weekAtMonth));
}
var targetDay = DateTimeCalcHelper.GetTargetDays(year, month, weekAtMonth, dayOfWeek);
if (targetDay > DateInfo.DaysInMonth(year, month))
{
return(DateInfo.InfinitePast);
}
return(DateInfoFactory.Create(year, month, targetDay));
}
public static DateInfo CreateLastDayOfMonth(int year, int month) => Create(year, month, DateInfo.DaysInMonth(year, month));
