get report group by weekly in c#

Question

In My project Enter data dayly Now I want have sum of record weekly or group data weekly, I try many methods, but got some error like:

.GroupBy( keySelector: d => __CurrentCulture_Calendar_0.GetWeekOfYear( time: d.ReportDate, rule: FirstDay, firstDayOfWeek: Saturday), elementSelector: d => d)'

This is my ViewModel (the same as Model) public class DataReportViewModels {

    public int TotalPCRTest { get; set; }
    public int TotalRapidTest { get; set; }
    public int PosPCRTest { get; set; }
    public int PosRapidTest { get; set; }
    public int PatientInCovid { get; set; }
    public int PatienPosInCovid { get; set; }
    public int PatientInICU { get; set; }
    public int TotalPosDeath { get; set; }
    public int TotalOutpatients { get; set; }
    [DataType(DataType.Date)]
    public DateTime ReportDate { get; set; }
}

and in my PageModel

      public IList<DataReportViewModels> ReportViewModelsw{ get; set; }



    IQueryable<DataReportViewModels> dataw = _context.DataReports.GroupBy(d => CultureInfo.CurrentCulture.Calendar.GetWeekOfYear
        (d.ReportDate, CalendarWeekRule.FirstDay, DayOfWeek.Saturday))
.Select(dat => new DataReportViewModels
           {
               //ReportDate = dat.Key,
               
               TotalPCRTest = dat.Sum(x => x.TotalPCRTest),
               TotalRapidTest = dat.Sum(x => x.TotalRapidTest),
               PosPCRTest = dat.Sum(x => x.PosPCRTest),
               PosRapidTest = dat.Sum(x => x.PosRapidTest),
               PatientInCovid = dat.Sum(x => x.PatientInCovid),
               PatienPosInCovid = dat.Sum(x => x.PatienPosInCovid),
               PatientInICU = dat.Sum(x => x.PaatientInICU),
               TotalPosDeath = dat.Sum(x => x.TotalPosDeath),

               TotalOutpatients = dat.Sum(x => x.TotalOutpatients)
           }).OrderByDescending(x => x.ReportDate);

        ReportViewModelsw = dataw.ToList();

Update my query

   var dataw = _context.DataReports.AsEnumerable().Where(x => x.Id > 1).GroupBy(d =>

               // ReportDate = d.ReportDate,
               (d.ReportDate.Day - 10) / 7)
           .Select(dat => new DataReportViewModels
           {


               TotalPCRTest = dat.Sum(x => x.TotalPCRTest),
               TotalRapidTest = dat.Sum(x => x.TotalRapidTest),
               PosPCRTest = dat.Sum(x => x.PosPCRTest),
               PosRapidTest = dat.Sum(x => x.PosRapidTest),
               PatientInCovid = dat.Sum(x => x.PatientInCovid),
               PatienPosInCovid = dat.Sum(x => x.PatienPosInCovid),
               PatientInICU = dat.Sum(x => x.PaatientInICU),
               TotalPosDeath = dat.Sum(x => x.TotalPosDeath),
               TotalOutpatients = dat.Sum(x => x.TotalOutpatients)
           });

And my table is normal table

   <table class="table table-striped table-hover">
            <caption>weekly report</caption>
            <thead>
                <tr>
                    <th>
                        @Html.DisplayNameFor(model => model.ReportViewModelsw[0].TotalPCRTest)
                    </th>
      ...
          </tr>
            </thead>
            <tbody>
                @foreach (var item in Model.ReportViewModelsw)
            {
                <tr>
                    <td>
                        @Html.DisplayFor(modelItem => item.TotalPCRTest)
                    </td>
                  ....
             </tr>
            }
            </tbody>
        </table>

Date time extention

public static class DateTimeExtensions
{
    public static DateTime StartOfWeek(this DateTime dt, DayOfWeek startOfWeek)
    {
        int diff = dt.DayOfWeek - startOfWeek;
        if (diff < 0)
        {
            diff += 7;
        }
        return dt.AddDays(-1 * diff).Date;
    }
}