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Contains() not working with query string that contains forward slash in ASP.NET MVC app

I am trying to implement a search function in my website that can search by date. It is a wildcard search, meaning the user can input anything and it will search multiple fields in the database.
An example URL is testsite.com/Note/SearchNotes?searchquery=6/27. And I have a record in the database with value 6/27/2022 5:44:24 PM in the DateCreated column.
public ActionResult SearchNotes(string searchquery)
{
var test = db.Notes.Where(Note => Note.DateCreated.ToString().Contains(searchquery)
|| /* check more properties */).ToList(); //returns 0
}
My problem is it is not returning any data when a query string such as "6/27" contains a forward slash. A string like "27" does return data. I believe / is a legal character, so I can't see why I am facing this problem.
One observation: it may be related to ToString() because forward slashes are returning data on properties that are already of type string.
Could anyone explain the reason for this behavior? Or better yet a solution?

DateTime.TryParse(#"6/27/2022 5:44:24 PM", out var dateCreated);
var notes = new List<string>
{
#"testsite.com/Note/SearchNotes?searchquery=6/27"
, #"Some Other Data"
, #"someOtherNote containing 27..."
, dateCreated.ToString()
, dateCreated.ToString("yyyy/MM/dd")
, dateCreated.ToString("MM/dd/yyyy")
, dateCreated.ToString("MM/dd/yyyy", System.Globalization.CultureInfo.InvariantCulture)
};
Console.WriteLine("test1");
var test = notes.Where(note => note.Contains("27")).ToList();
foreach (var result in test)
Console.WriteLine(result);;
Console.WriteLine();
Console.WriteLine("test2");
var test2 = notes.Where(note => note.Contains("/27")).ToList();
foreach (var result in test2)
Console.WriteLine(result);
produces
test1
testsite.com/Note/SearchNotes?searchquery=6/27
someOtherNote containing 27...
2022-06-27 17:44:24
2022-06-27
06-27-2022
06/27/2022
test2
testsite.com/Note/SearchNotes?searchquery=6/27
06/27/2022
which I think answers your question. DateTime formatting, culture, machine- and user-regional environment settings / localization is all a bit of dark art and to be sure that you find date (parts) by string-matching you must be sure to match format.
Note that even the explicit format "MM/dd/yyyy" produced output formatted "MM-dd-yyyy" until I specified CultureInfo.InvariantCulture

Unity3d rearrange a string

Say you have a string 5/9/2010 and you want to rearrange it to read 2010/5/9. How would you go about doing that?
I want to sort a list by a string that happens to be a date. While I could make it into a date, I want to stick with a string, if possible because the time part of the datetime is hard to eliminate. (This is being used in an sqlite database for a Unity3d App.)
Forgive me if this is a duplicate.

If you can guarantee that the string will always be the same input format, you can split the string on the /:
string input = "5/9/2010";
string[] inputSections = input.Split('/');
string output = string.Format("{0}/{1}/{2}", inputSections[2], inputSections[0], inputSections[1]);
Working Fiddle
My code is very verbose, you can certainly simplify it for your needs. I would also utilize the string inerpolation feature of C# 6 if it is available to you:
string input = "5/9/2010";
string[] inputSections = input.Split('/');
string output = $"{inputSections[2]}/{inputSections[1]}/{inputSections[0]}";

I would recommend parsing the date, in the off chances that the input date is not exactly in the format you were expecting, but was indeed a valid date. This is the situations parsing is for.
CultureInfo us = CultureInfo.GetCultureInfo("en-US");
string input = "5/9/2010";
DateTime date = DateTime.Parse(input, us);
Console.WriteLine(date.ToString("yyyy/MM/dd", us));
You can test here

Parse date of ISO 8601 value 24:00:00 fails

I'm trying to parse incoming date from data source (which cannot be changed). It gives me time in ISO 8601 format example: 2007-04-05T24:00.
How ever in .Net it fails to parse this as valid time.
The wikipedia states that it should be valid format. Wikipedia ISO 8601
Example from https://stackoverflow.com/a/3556188/645410
How can I do this without a nasty string check hack?
Example (fiddle: http://dotnetfiddle.net/oB7EZx):
var strDate = "2007-04-05T24:00";
Console.WriteLine(DateTime.Parse(strDate, null, DateTimeStyles.RoundtripKind));
Throws:
The DateTime represented by the string is not supported in calendar
System.Globalization.GregorianCalendar.

Yes, .NET doesn't support this as far as I'm aware.
My Noda Time project does, but only partially: it can parse the value, but the value is just parsed to midnight at the start of the next day, and is never formatted as 24:00. There's nothing in the Noda Time conceptual model to represent "the end of the day".
Sample code to show what's possible:
using System;
using NodaTime;
using NodaTime.Text;
class Test
{
static void Main()
{
string text = "2007-04-05T24:00";
var pattern = LocalDateTimePattern.CreateWithInvariantCulture
("yyyy-MM-dd'T'HH:mm");
var dateTime = pattern.Parse(text).Value;
Console.WriteLine(pattern.Format(dateTime)); // 2007-04-06T00:00
}
}
If you don't mind losing the difference between inputs of "2007-04-05T24:00" and "2007-04-05T00:00" then you're probably okay.

Here is one simple solution — it updates this kind of end-of-the-day values to the start-of-the-next-day:
using System;
using System.Text.RegularExpressions;
namespace Iso8601ToDateTime
{
class Program
{
string text = "2021-12-31T24:00:00+01:00";
var pattern = #"^([-\d]+)(T24)";
var replaced = Regex.Replace(text, pattern,
m => DateTime.Parse(m.Groups[1].Value)
.AddDays(1).ToString("yyyy-MM-dd") + "T00");
Console.WriteLine(replaced); // 2022-01-01T00:00:00+01:00
}
}
UPDATED: Fixed bug based on raznagul's comment.

Formatting string dates with String.Format()

Just curious...
So I get that if I convert the string version of the date to a DateTime object and pass it into the String.Format() method, then I"ll get the desired results.
String.Format("The date is {0:MMMM dd, yyyy}", DateTime.Parse("05-22-2012"));
"The date is May 22, 2012"
But why doesn't this work?
String.Format("The date is {0:MMMM dd, yyyy}", "05-22-2012")
"The date is 05-22-2012"
Sorry if this is a stupid question, but I'm just trying to understand how this works.
Thanks

The other answers here hit on salient points, but let's put them all together an examine how String.Format works.
It has five overloads, but we're going to talk only about the one that they all redirect to (this is not the actual code, if you want to see it with Reflector or ILSpy, you will find it in StringBuilder.AppendFormat). This is simplified for easy understanding.
public static string Format(IFormatProvider provider, string format, params object[] args)
{
StringBuilder sb = new StringBuilder();
// Break up the format string into an array of tokens
Token[] tokens = ParseFormatString(format);
foreach (Token token in tokens)
{
switch (token.TokenType)
{
// A Text token is just some text to output directly
case TokenType.Text:
sb.Append(token.Text);
break;
// An Index token represents something like {0} or {2:format}
// token.Index is the argument index
// token.FormatText is the format string inside ('' in the first example, 'format' in the second example)
case TokenType.Index:
{
object arg = args[token.Index];
IFormattable formattable = arg as IFormattable;
if (formattable != null && token.FormatText.Length > 0)
{
// If the argument is IFormattable we pass it the format string specified with the index
sb.Append(formattable.ToString(token.FormatText, provider));
}
else
{
// Otherwise we just use Object.ToString
sb.Append(arg.ToString());
}
}
break;
}
}
return sb.ToString();
}
In your question you ask why the format string doesn't get applied when you pass "05-22-2012". As Guffa said, that is not a DateTime object, it is a String object.
As GSerjo said, a String is not IFormattable. Strings are not formattable because formatting is the process of converting something into a String. A string is already a string!
So you can see that when the Format method gets to indexer, arg will not be IFormattable and it will simply call ToString. Calling ToString on a string simply returns itself, it's already a string.
In summary, if your format string contains an index with an inner-format string (e.g. {0:format}), that inner-format string will only be applied if the associated argument is IFormattable and it knows what to do with the format string you give it.

A custom datetime format only works on a DateTime value. If you are using a string instead, the format will be ignored because there is only one way to output a string.

Because "05-22-2012" is not IFormattable, DateTime.Parse("05-22-2012") it's DateTime
please look here for more examples
String Format for DateTime
Custom Date and Time Format Strings

Convert DateTime with TypeDescriptor.GetConverter.ConvertFromString (using custom format)

Is there any way to make
TypeDescriptor.GetConverter.ConvertFromString convert to DateTime using a custom format e.g. "2011-04-21 13-03-56"?
If not, is there any DateTime-format out there that can be applied to a folder name (/,\,:,etc. are not allowed as you know)?
Help is very much appreciated. Thanks in advance
Random-I-Am
Edit:
Since my request still seems to not be understood correctly I am again trying to elaborate on my question. My users are creating folders with specific names. For example "1000_Link_Topic1_2011-01-25 14-12-10". They are free to combine their information as they like and omit information where needed. They don't even have to care about case sensitivity. So I could face another folder named "1000_link_Topic2".
What I have is a single class with a single property for each possible fragment of information. In this case I would have (Since I had to find a way of checking each properties default value regardless of the property type I am using nullable types):
Short? short_val;
EContentType? enum_val;
String string_val;
DateTime? datetime_val;
My code obviously splits the folder name at "_" and then tells for each fragment to which of the above property types it belongs. As soon as I know the corresponding type I am trying to convert to the Type, lets say t, using TypeDescriptor.GetConverter(t).ConvertFromString(info_frag[i]). I hope you now understand why I cannot use another conversion Method.
The code works for all the types mentioned above. My problem is to find a custom DateTime format that can be used on a folder name. All of the formats I know are using colons to separate hours from minutes and seconds.
What I want is a way to convert from a custom DateTime-format to a DateTime-object using TypeDescriptor.GetConverter.ConvertFromString. If that is not possible I either need to find a standard DateTime-format which can be assigned as a folder name without any further conversion or somehow extend the built-in DateTime-formats by my custom format. If it is going to be the latter I do not care about being able to use seconds or minutes. Hours will do the job.
Thanks again for being as patient as you are and helping me out with this one. Feel free to ask as many further questions as you like. I hope you can help me getting this one to work.
Random-I-Am

I have looked into your problem a little and found that the standard DateTimeTypeConverter uses DateTime.Parse internally which doesn't listen to CurrentCulture info at all. Instead you can trick the conversion process with your own TypeConverter!
I do not know how to attach the new typeconverter to the existing DateTime structure, if you even can, so I made a miniture AdvancedDateTime structure .. which is empty. Noone said your custom TypeConvert should even return such a thing! This one returns a regular DateTime. I provided the code below:
public class CustomDateTimeTypeConverter : TypeConverter
{
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
return DateTime.ParseExact(value.ToString(), "yyyy-MM-dd HH-mm-ss", culture);
}
}
[TypeConverter(typeof(CustomDateTimeTypeConverter))]
struct AdvancedDateTime
{
}
[TestFixture]
public class DateTime
{
[Test]
public void TypeConvert_StrangeFormat_ConvertsWithoutProblem()
{
string datetime = "2011-04-21 23-12-13";
TypeConverter converter = TypeDescriptor.GetConverter( typeof (AdvancedDateTime) );
var convertedFromString = converter.ConvertFromString(datetime);
Assert.AreEqual(new DateTime(2011,4,21, 23,12,13), convertedFromString);
}
}

Try this
string m_strDate = DateTime.Now.ToString("MM/dd/yyyy");
m_strDate = m_strDate.Replace("/", "");
Append this m_strDate to your folder
A sample i used for text file is as follows
strPath += "/FileHeader_" + m_strDate + ".txt";
Check this sample
DateTime dt=new DateTime(1990,5,6);
Console.WriteLine(TypeDescriptor.GetConverter(dt).ConvertTo(dt, typeof(string)));
string myStr="1991-10-10";
Console.WriteLine(TypeDescriptor.GetConverter(dt).ConvertFrom(myStr));
The sample code i written just to display as per you need try as per your requirement
string s = "Folder";
DateTime dt = new DateTime(1990, 5, 6);
string str = TypeDescriptor.GetConverter(dt).ConvertTo(dt, typeof(string)).ToString();
string myStr = "1991-10-10";
string str1 = TypeDescriptor.GetConverter(dt).ConvertFrom(myStr).ToString();
s = s + str1.Replace("/", "").Replace(":", "");
textBox1.Text = s;