Month ("M", "m") Format Specifier in C#

The Month ("M", "m") format specifier in C# represents a custom date and time format string that displays the month and day portions of a date. This format specifier is defined by the current DateTimeFormatInfo.MonthDayPattern property and typically follows the pattern MMMM dd.

Syntax

Following is the syntax for using the Month format specifier −

dateTime.ToString("M")
dateTime.ToString("m")

The custom format string pattern is −

MMMM dd

Using Month Format Specifier

Basic Example

using System;
using System.Globalization;

class Demo {
    static void Main() {
        DateTime date = new DateTime(2018, 6, 11, 9, 15, 0);
        Console.WriteLine(date.ToString("m", CultureInfo.CreateSpecificCulture("en-us")));
        Console.WriteLine(date.ToString("M", CultureInfo.CreateSpecificCulture("en-us")));
    }
}

The output of the above code is −

June 11
June 11

Different Culture Formats

using System;
using System.Globalization;

class Demo {
    static void Main() {
        DateTime date = new DateTime(2023, 12, 25, 14, 30, 0);
        
        Console.WriteLine("English (US): " + date.ToString("M", CultureInfo.CreateSpecificCulture("en-US")));
        Console.WriteLine("French: " + date.ToString("M", CultureInfo.CreateSpecificCulture("fr-FR")));
        Console.WriteLine("German: " + date.ToString("M", CultureInfo.CreateSpecificCulture("de-DE")));
        Console.WriteLine("Current Culture: " + date.ToString("M"));
    }
}

The output of the above code is −

English (US): December 25
French: 25 décembre
German: 25. Dezember
Current Culture: December 25

Comparison with Other Date Formats

Custom Pattern Access

using System;
using System.Globalization;

class Demo {
    static void Main() {
        CultureInfo culture = CultureInfo.CreateSpecificCulture("en-US");
        Console.WriteLine("Month-Day Pattern: " + culture.DateTimeFormat.MonthDayPattern);
        
        DateTime date = new DateTime(2023, 3, 8);
        Console.WriteLine("Using 'M' specifier: " + date.ToString("M", culture));
        Console.WriteLine("Using custom pattern: " + date.ToString(culture.DateTimeFormat.MonthDayPattern, culture));
    }
}

The output of the above code is −

Month-Day Pattern: MMMM dd
Using 'M' specifier: March 08
Using custom pattern: March 08

Conclusion

The Month format specifier ("M" or "m") in C# provides a culture-sensitive way to display month and day information. It automatically adapts to different locales and follows the MonthDayPattern defined in the current culture's DateTimeFormatInfo.