DateTime parsing

Question

I am writing a syslog server that receives syslog messages and stores them in a database.

I am trying to parse the date string received in the message into a DateTime structure.

For the following examples, I'll be using an underscore in place of whitespace for clarity; the actual strings received have spaces.

The string I received is in the format "Jun__7_08:09:10" - please note the two whitespaces between the month and day.

If the day is after the 10th, the strings become "Jun_10_08:09:10" (one whitespace).

If I parse with:

DateTime.ParseExact(Log.Date, "MMM  d HH:mm:ss", CultureInfo.InvariantCulture);

it works for strings from the 1st to 9th but throws exception from the 10th forward, and if I parse with one space, it throws an exception on the 1st to 9th (and works from the 10th on).

What is the correct way to parse this string?

Answer 1

Use the DateTime.ParseExact overload that takes an array of format strings:

DateTime.ParseExact(Log.Date, 
                    new [] {"MMM  d HH:mm:ss", "MMM d HH:mm:ss"}, 
                    CultureInfo.InvariantCulture,
                    DateTimeStyles.None);

Answer 2

DateTime's ParseExect Method has some overloads where you can pass multiple format that could be readed if the earlier one is not working. here a sample for you..

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      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)
      {
         try {
            dateValue = DateTime.ParseExact(dateString, formats, 
                                            new CultureInfo("en-US"), 
                                            DateTimeStyles.None);
            Console.WriteLine("Converted '{0}' to {1}.", dateString, dateValue);
         }
         catch (FormatException) {
            Console.WriteLine("Unable to convert '{0}' to a date.", dateString);
         }                                               
      }
   }
}
// The example displays the following output:
//       Converted '5/1/2009 6:32 PM' to 5/1/2009 6:32:00 PM.
//       Converted '05/01/2009 6:32:05 PM' to 5/1/2009 6:32:05 PM.
//       Converted '5/1/2009 6:32:00' to 5/1/2009 6:32:00 AM.
//       Converted '05/01/2009 06:32' to 5/1/2009 6:32:00 AM.
//       Converted '05/01/2009 06:32:00 PM' to 5/1/2009 6:32:00 PM.
//       Converted '05/01/2009 06:32:00' to 5/1/2009 6:32:00 AM.

Answer 3

Consider using this line:

DateTime.ParseExact(Log.Date,
    "MMM d HH:mm:ss",
    CultureInfo.InvariantCulture,
    DateTimeStyles.AllowWhiteSpaces);

Notice that I removed one of the spaces between the month and the day. That's because AllowWhiteSpaces literally means:

Specifies that s may contain leading, inner, and trailing white spaces not defined by format.

Answer 4

    DateTime.ParseExact(date, "MMM d HH:mm:ss", CultureInfo.InvariantCulture,DateTimeStyles.AllowInnerWhite)

Answer 5

You could remove the extra space first and then parse the string:

DateTime.ParseExact(Log.Date.Replace("  ", " "), "MMM d HH:mm:ss", CultureInfo.InvariantCulture);