public IActionResult OnPostSelectAll([FromQuery] int?year, [FromQuery] int?month, [FromQuery] int?day)
        {
            if (!year.HasValue || !month.HasValue || !day.HasValue)
            {
                return(RedirectToPage("Index", new { year, month, day }));
            }
            var pageResult = PageResult(year.Value, month.Value, day.Value);

            SelectedDates.Clear();
            foreach (var date in SelectedDate.ToYearMonth().ToDateInterval())
            {
                SelectedDates.Add(LocalDatePattern.CreateWithInvariantCulture("yyyy-MM-dd").Format(date));
            }
            return(pageResult);
        }