public static void Main()
DateTime dateValueFromDateTime;
DateTime dateValueToDate;
DateTime.TryParse("2020-02-15 18:00:00", out dateValueFromDateTime);
DateTime.TryParse("2020-02-18", out dateValueToDate);
Console.WriteLine(dateValueFromDateTime);
Console.WriteLine(dateValueFromDateTime.Date);
Console.WriteLine(dateValueToDate.Date);
Console.WriteLine((dateValueFromDateTime - dateValueToDate.Date).Days);
Console.WriteLine((dateValueFromDateTime.Date - dateValueToDate.Date).Days);