我可以在list中使用匿名类型吗?而不是助手类

我需要一个包含一些对象的列表来进行计算。

我当前的代码是这样的

private class HelperClass
{
    public DateTime TheDate {get;set;}
    public TimeSpan TheDuration {get;set;}
    public bool Enabled {get;set;}
}
private TimeSpan TheMethod()
{
    // create entries for every date
    var items = new List<HelperClass>();
    foreach(DateTime d in GetAllDatesOrdered())
    {
        items.Add(new HelperClass { TheDate = d, Enabled = GetEnabled(d), });
    }
    // calculate the duration for every entry
    for (int i = 0; i < items.Count; i++)
    {
        var item = items[i];
        if (i == items.Count -1) // the last one
            item.TheDuration = DateTime.Now - item.TheDate;
        else
            item.TheDuration = items[i+1].TheDate - item.TheDate;
    }
    // calculate the total duration and return the result
    var result = TimeSpan.Zero;
    foreach(var item in items.Where(x => x.Enabled))
        result = result.Add(item.TheDuration);
    return result;
}

现在我发现仅仅为我的计算引入一个类型(HelperClass)有点难看。我的第一种方法是使用Tuple<DateTime, TimeSpan, bool>，就像我通常这样做，但因为我需要在创建实例后修改TimeSpan，我不能使用Tuple，因为Tuple.ItemX是只读的。

我想到了一个匿名类型，但是我不知道如何初始化我的List

var item1 = new { TheDate = DateTime.Now,
                  TheDuration = TimeSpan.Zero, Enabled = true };
var items = new List<?>(); // How to declare this ???
items.Add(item1);

// Materialize the result to avoid computing possibly different sequences
var allDatesAndNow = GetDatesOrdered().Concat(new[] { DateTime.Now })
                                      .ToList();
return allDatesNow.Zip(allDatesNow.Skip(1),
                       (x, y) => new { Enabled = GetEnabled(x),
                                       Duration = y - x })
                  .Where(x => x.Enabled)
                  .Aggregate(TimeSpan.Zero, (t, pair) => t + pair.Duration);

var itemsWithoutDuration = GetAllDatesOrdered()
    .Select(d => new { TheDate = d, Enabled = GetEnabled(d) })
    .ToList();
var items = itemsWithoutDuration
    .Select((it, k) => new { TheDate = it.d, Enabled = it.Enabled, 
         TheDuration = (k == (itemsWithoutDuration.Count - 1) ? DateTime.Now : itemsWithoutDuration[k+1].TheDate) - it.TheDate })
    .ToList();