Supporting 13 months

Daily Knowledge Drop

.NET has support for 13 months - the Hebrew and EastAsianLunisolarCalendar for example, has the concept of leap months, and as such it is possible for a year to consist of 13 months.

GetMonthName

The GetMonthName method on DateTimeFormatInfo supports a month parameter value of between 1 and 13.

For calendars which only support 12 months, sending a value of 13 to the GetMonthName method will return a blank string:

// this will use the current 
// culture calendar
var df = new DateTimeFormatInfo();

Console.WriteLine(df.GetMonthName(1));
Console.WriteLine(df.GetMonthName(13));

The output of this is:

January

However, if we switch using a Calendar which supports 13 months:

// switch the culture and the calendar
HebrewCalendar hc = new HebrewCalendar();
CultureInfo culture = CultureInfo.CreateSpecificCulture("he-IL");
culture.DateTimeFormat.Calendar = hc;
Thread.CurrentThread.CurrentCulture = culture;

// output to the debug window as my Console did not
// support the characters
Debug.WriteLine(culture.DateTimeFormat.GetMonthName(1));
Debug.WriteLine(culture.DateTimeFormat.GetMonthName(13));

Now the output is as follows:

תשרי
אלול

The Debug output is used here instead of the Console, as my default Console Window encoding did not support Hebrew characters (while the Visual Studio output window does by default)

Notes

This piece of knowledge is not especially useful or relevent unless one is working with one of the specific calendars/cultures, or one has to support multiple cultures in the application. It also serves as a reminder that the culture an application executes under is important, and not to always make assumptions about how the application will always operate.

References

Misconceptions: 1 year = 12 months

Daily Drop 208: 23-11-2022

At the start of 2022 I set myself the goal of learning one new coding related piece of knowledge a day.
It could be anything - some.NET / C# functionality I wasn't aware of, a design practice, a cool new coding technique, or just something I find interesting. It could be something I knew at one point but had forgotten, or something completely new, which I may or may never actually use.

The Daily Drop is a record of these pieces of knowledge - writing about and summarizing them helps re-enforce the information for myself, as well as potentially helps others learn something new as well.