How can I parse dates with a suffix "th", "st" or "nd" on the day of the month?

I'm having trouble using DateTime.Parse

I'm handling a variety of formats of dates and some of which are of the formatJanuary 11th or February 22nd and so on.

DateTime.Parse throws an exception trying to parse these sort of dates.

I was wondering if there is a built in functionality in DateTime that I am missing, like a flag I can set that will make Parse behave in a more acceptable way.

I am aware that this is solvable with a relatively simple regular expression, moreover I already have a class that fuzzy matches dates that I wrote, however I would like to know if there is a built in way to perform this sort of extraction since it will more likely be easier to maintain in the long run than reinventing the wheel.

There isn't anything inbuilt in .Net framework to parse dates in format of January 11th or February 22nd etc. You have to remove the suffix characters and then you can use DateTime.TryParseExact.

For dates with Suffix st, th, you can use string.Replace to remove that part and then use DateTime.TryParseExact. Like.

string str = "1st February 2013";
DateTime dtObject;
string replacedStr =  str.Substring(0,4)
                         .Replace("nd","")
                         .Replace("th","")
                         .Replace("rd","")
                         .Replace("st","")
                         + str.Substring(4);


if (DateTime.TryParseExact(replacedStr, 
                            "dd MMMMM yyyy", 
                            CultureInfo.InstalledUICulture, 
                            DateTimeStyles.None, 
                            out dtObject))
{
 //valid date
}

For multiple formats, you can specify the formats in a string array and later you can use that. It returns a bool value indicating if the parsing was successful or not.

Example from MSDN:

string[] formats= {"M/d/yyyy h:mm:ss tt", "M/d/yyyy h:mm tt", 
                   "MM/dd/yyyy hh:mm:ss", "M/d/yyyy h:mm:ss", 
                   "M/d/yyyy hh:mm tt", "M/d/yyyy hh tt", 
                   "M/d/yyyy h:mm", "M/d/yyyy h:mm", 
                   "MM/dd/yyyy hh:mm", "M/dd/yyyy hh:mm"};
string[] dateStrings = {"5/1/2009 6:32 PM", "05/01/2009 6:32:05 PM", 
                        "5/1/2009 6:32:00", "05/01/2009 06:32", 
                        "05/01/2009 06:32:00 PM", "05/01/2009 06:32:00"}; 
DateTime dateValue;

foreach (string dateString in dateStrings)
{
   if (DateTime.TryParseExact(dateString, formats, 
                              new CultureInfo("en-US"), 
                              DateTimeStyles.None, 
                              out dateValue))
      Console.WriteLine("Converted '{0}' to {1}.", dateString, dateValue);
   else
      Console.WriteLine("Unable to convert '{0}' to a date.", dateString);

This is a very old question, however for anyone still looking into complex natural language date parsing I'd recommend using nChronic, a .NET port of the amazing (ruby based) chronic date parser.

The source for it is here: nChronic Github

It's also in Nuget as Chronic: Chronic in Nuget

Some very simple example code using this library would be like such:

using Chronic;
var parser = new Chronic.Parser ();
Span ParseObj;
DateTime ParsedDateTime;
ParseObj = parser.Parse ("January 11th");
ParsedDateTime = ParseObj.Start;

Here are some examples of what it can handle:

Simple

thursday
november
summer
friday
13:00
mon 2:35
4pm
10 to 8
10 past 2
half past 2
6 in the morning
friday 1pm
sat 7 in the evening
yesterday
today
tomorrow
last week
next week
this tuesday
next month
last winter
this morning
last night
this second
yesterday at 4:00
last friday at 20:00
last week tuesday
tomorrow at 6:45pm
afternoon
yesterday
thursday last week

Complex

3 years ago
a year ago
5 months before now
7 hours ago
7 days from now
1 week hence
in 3 hours
1 year ago tomorrow
3 months ago saturday at 5:00 pm
7 hours before tomorrow at noon
3rd wednesday in november
3rd month next year
3rd thursday this september
4th day last week
fourteenth of june 2010 at eleven o'clock in the evening
may seventh '97 at three in the morning

Specific Dates

January 5
22nd of june
5th may 2017
February twenty first
dec 25
may 27th
October 2006
oct 06
jan 3 2010
february 14, 2004
february 14th, 2004
3 jan 2000
17 april 85
5/27/1979
27/5/1979
05/06
1979-05-27
Friday
5
4:00
17:00
0800

Specific Times (many of the above with an added time)

January 5 at 7pm
22nd of june at 8am
1979-05-27 05:00:00
03/01/2012 07:25:09.234567

etc

I had similar problem here's better way

  stringdate="August 19th 2000" 
  string pattern = @"\b(\d+)(?:st|nd|rd|th)\b";
  Regex rgx = new Regex(pattern);
  DateTime.Parse(String.Format("{0:MMMM,  d, yyyy}", rgx.Replace(stringdate, "$1"))  
  **result**    {19/08/2000 00:00:00}   System.DateTime

From Microsoft and regex to remove ordinals and How can I visualize the way various DateTime formats will display?

EDIT

If the year is not specified:

    stringdate= rgx.Replace(stringdate, "$1");
    DateTime datetime;
    if (!DateTime.TryParseExact(stringdate, "MMMM dd yyyy", System.Globalization.DateTimeFormatInfo.InvariantInfo, System.Globalization.DateTimeStyles.None, out datetime))
    {
     // assuming no gap exist
     datetime = DateTime.Parse(stringdate += " "+DateTime.Now.Year);
    }

Now if the input string text is "June 11th", it will be 11/6/2021.

There are More functions and ways to handle dates at DateTime Documentation.

If you dont want the year at all, then you can add the following line:

datetime.ToString("MM/dd");

Now the output will be "11/6"

How can I parse dates with a suffix "th", "st" or "nd" on the day of the month?

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