JavaScript

DA=new Intl.Locale('ja-JP');  //日本語の日本国。
D=DA.calendars;  //＝[object]：gregory,japanese
	//0＝[string]：gregory
	//1＝[string]：japanese
DA=new Intl.Locale('ja');  //日本語。
D=DA.calendars;  //＝[object]：gregory,japanese
	//0＝[string]：gregory
	//1＝[string]：japanese
DA=new Intl.Locale('ar-EG');  //アラビア語のエジプト国。
D=DA.calendars;  //＝[object]：gregory,coptic,islamic,islamic-civil,islamic-tbla
	//0＝[string]：gregory
	//1＝[string]：coptic
	//2＝[string]：islamic
	//3＝[string]：islamic-civil
	//4＝[string]：islamic-tbla

DA=new Intl.Locale('en');  //英語。
D=DA.calendars;  //＝[object]：gregory
	//0＝[string]：gregory
DA=new Intl.Locale('en', {calendar:'japanese'});  //英語、歴指定。
D=DA.calendars;  //＝[object]：japanese
	//0＝[string]：japanese

→Intl.Locale()。言語タグ