public Report Build()
{
var weekPeriods = Weeks.Select(w => new WeekPeriod
(
startedOn: w.StartedOn.Day,
finishedOn: w.FinishedOn.Day,
rates: w.GetRateInfos()
)).ToArray();
return(new Report(string.Format("{0:yyyy}", Weeks[0].StartedOn), string.Format("{0:MMMM}", Weeks[0].StartedOn), weekPeriods));
}