Sort list by date closest to now but not old dates

Question

I have a list with dates that I would like to sort according to:

• Dates that is today should be sorted in the top
• Dates that is in the future should be sorted by closest date today (example today = 8th and we have the dates 18, 9, 11 should be sorted => 9, 11, 18)
• Dates older then today's date should be listed in the bottom of the list descending.

What is the best way to do this ?:

• Is it to create a future list,

• old list and present list and then concat and sort them?

• Or can i achieve this in a better way?

To to make this even clearer this is how the sorted list should look like:

today => tomorrow => day after tomorrow => days in future.... => yesterday => older then yesterday

Answer 1

var dates = new List<DateTime>()
{
    DateTime.Today,
    DateTime.Today.AddDays(1),
    DateTime.Today.AddDays(-2),
    DateTime.Today.AddDays(5),
    DateTime.Today.AddDays(-5)
};

Dates that is today should be sorted in the top

DateTime today = dates.Where(x => x == DateTime.Today).First();

Dates that is in the future should be sorted by closest date today (example today = 8th and we have the dates 18, 9, 11 should be sorted => 9, 11, 18)

List<DateTime> futureDates = dates.Where(x => x > today).ToList();
futureDates.Sort();

Dates older then today's date should be listed in the bottom of the list descending.

List<DateTime> oldDates = dates.Where(x => x < today).OrderByDescending(x => x).ToList();

And this is the final aggregated result:

var final = new List<DateTime>();
final.Add(today);
final.AddRange(futureDates);
final.AddRange(oldDates);

<== Fiddle ==>