How to calculate days, ignoring the hours?

Question

How can I calculate if spent 1 day ignoring the hours. Explaining, it would be more or less like this:

I have a date 2017-09-09 11:45:20, normally it would have been a day when the 11:45 the other day, but I’d like it to count as 1 day as soon as it 00:00:00.

Even though I have the following date 2017-09-09 23:59:59 and now was 2017-09-10 00:00:00. Literally just went by 1 minute, but I want you to tell me how 1 day.

I tried to do it this way, but I returned 0:

//                          mês/dia/ano hora:min:seg
// questData.CompletedDate   09/09/2017 11:45:20
// DateTime.Today            09/10/2017 00:00:00
int totalDays = (int)DateTime.Today.Subtract(questData.CompletedDate).TotalDays;

How to do this in C#?

Answer 1

Just take only part of days with the property Date of DateTime.

using System;
using static System.Console;

public class Program {
    public static void Main() => WriteLine((new DateTime(2017, 09, 10, 11, 45, 00).Date - new DateTime(2017, 09, 09, 11, 45, 20).Date).TotalDays);
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.