register-holiday-calendar

name	Register Holiday Calendar
description	Register a new holiday calendar in the HolidayCalendar enum

How to Register a Holiday Calendar

This guide explains how to register a new country calendar in the HolidayCalendar enum.

File Location

Edit: jollyday-core/src/main/java/de/focus_shift/jollyday/core/HolidayCalendar.java

Organization Pattern

The HolidayCalendar enum follows a strict organization pattern:

1. Calendars are listed in alphabetical order by their ISO country code
2. Each line starts with calendars beginning with a specific letter (A, B, C, etc.)
3. Multiple calendars sharing the same starting letter are grouped on the same line alphabetically

Example Structure

public enum HolidayCalendar {
  ANTARCTICA("AQ"), ALBANIA("AL"), ANDORRA("AD"), ARGENTINA("AR"), ARMENIA("AM"), AUSTRALIA("AU"), AUSTRIA("AT"),
  BAHAMAS("BS"), BELARUS("BY"), BELGIUM("BE"), BERMUDA("BM"), BOLIVIA("BO"), BRAZIL("BR"), ...
  CANADA(Locale.CANADA.getCountry()), CAYMAN_ISLANDS("KY"), ...
  GERMANY("DE"), GREECE("GR"), ...
  UNITED_STATES(Locale.US.getCountry()), ...
}

Steps to Add Your Calendar

1. Find the Correct Line

Identify which line your country code should appear on based on the first letter:

First Letter	Example Calendars
A	ANTARCTICA, ALBANIA, ANDORRA, ARGENTINA, AUSTRALIA
B	BELARUS, BELGIUM, BERMUDA, BRAZIL
D	DENMARK, DOMINICAN, ECUADAR (E starts D line)

2. Insert in Alphabetical Order

Add your calendar in alphabetical position within that letter group:

Before:

ALBANIA("AL"), ANDORRA("AD"), ARGENTINA("AR"),

Adding Antarctica (AQ) - after ARGENTINA:

ALBANIA("AL"), ANDORRA("AD"), ARGENTINA("AR"), ANTARCTICA("AQ"),

3. Use Correct Format

Format: COUNTRY_NAME("ISO_CODE")

Examples:

GERMANY("DE"),                          // Direct ISO code
CANADA(Locale.CANADA.getCountry()),     // Java Locale for special cases
UNITED_STATES(Locale.US.getCountry()),  // Java Locale for US

Complete Example

Adding a fictional "Zebra" country with code "ZB":

Before:

  ZIMBABWE("ZW");
}

After:

  ZEBRA("ZB"), ZIMBABWE("ZW");
}

Special Cases

Some countries use Java Locale instead of string codes:

CANADA(Locale.CANADA.getCountry()),  // Returns "CA"
UNITED_STATES(Locale.US.getCountry()),  // Returns "US"

Best Practices

1. Alphabetical order: Always maintain alphabetical order by ISO code
2. Proper naming: Use full country name in uppercase with underscores
3. ISO code: Use the official ISO 3166-1 alpha-2 code
4. Comma placement: Add comma after each entry except the last
5. Semicolon: Last entry ends with semicolon before closing brace

Verification

After adding your calendar, verify:

1. The calendar is in the correct alphabetical position
2. The ISO code matches the XML file's hierarchy attribute
3. The Java file compiles without errors